jntuexamspapers

Code No: V0101/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

PROBABILITY AND STATISTICS

( Common to Civil Engineering, Mechanical Engineering, Chemical

Engineering, Mechatronics, Production Engineering, Bio-Technology and

Automobile Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Define a random experiment, sample space, event and mutually exclusive

events. Give examples of each.

(b) Box A contains 5 red and 3 white marbles and box B contains 2 red and 6

white marbles.

i. If a marble is drawn from each box, what is the probability that they are

both of the same colour? [8+8]

2. (a) Define random variable, discrete probability distribution, continuous proba-

bility distribution and cumulative distribution. Give an example of each.

(b) The mean of Binomial distribution is 3 and the variance is

. Find

i. The value of n

ii. p(

x 7)

iii. p(1

x < 6). [8+8]

3. (a) A poisson distribution is such that p(x=0) = p(x=1). Find the probability

that

i. p(0

< x 3)

ii. p(1

x <4)

iii. p(x

(b) Assuming that the diameters of 1000 brass plugs taken consecutively from a

machine for a normal distribution with mean .7515 cms and S.D .002 cms.

How many plugs are likely to be rejected, if the approximated diameter is

.752

±.004. [8+8]

4. Samples of size 2 are taken from the population 4, 8, 12, 16, 20, 24 without re-

placement. Find

(a) mean of the population

(b) standard deviation of population

(d) standard deviation of sampling distribution of means. [16]

5. (a) The mean and the standard deviation of a population are 11,795 and 14,054

respectively. If n=50, find 95% confidence internal for the mean

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Code No: V0101/R05

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(b) In a city 250 men out of 750 were found to be smokers. Does this information

support the conclusion that the majority of men in this city are smokers.[8+8]

6. (a) To examine the hypothesis that the husbands are more intelligent than the

wives, an investigator took a sample of 10 couples and administered them a

test which measures the IQ as follows:

Test the hypothesis with a reasonable test at the level of significance of 0.05?

Husbands: 117 105 97 105 123 109 86 78 103 107

Wives 106 98 87 104 116 95 90 69 108 85

(b) In an investigation on the machine performance the following results were

obtained:

No.of Units inspected No. of defectives

Machine 1 375 17

Machine 2 450 22

Test whether there is any significant performance of two machines at

=0.05

[8+8]

7. (a) Fit a straight line for the following data

x 1 2 3 4 5 6 7 8 9 10

y 52.5 58.7 65 70.2 75.4 81.1 87.2 95.5 102.2 108.4

(b) Fit a curve of the form y =

by the method of least squares for the following

data and estimate the value of y when x = 300. [8+8]

x 77 100 185 239 285

y 2.4 3.4 7.0 11.1 19.6

8. The following data relate to the marks of 10 students in the internal test and the

university examination for the maximum of 50 each

Internal marks (x) 25 28 30 32 35 36 38 39 42 45

University marks (y) 20 26 29 30 25 18 26 35 35 46

Find the coefficient of correlation and the two lines of regression. [16]

? ? ? ? ?

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Code No: V0101/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

PROBABILITY AND STATISTICS

( Common to Civil Engineering, Mechanical Engineering, Chemical

Engineering, Mechatronics, Production Engineering, Bio-Technology and

Automobile Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) For any three arbitrary events A, B, C prove that

(A0 [ B0 [ C) = P(A) + P(B) + P(C) − P(A \ B) − P(B \ C) − P(C \

) + P(A \ B \ C)

(b) In a certain town 40% have brown hair, 25% have brown eyes and 15% have

both brown hair and brown eyes. A person is select at random from the town

i. If he has brown hair, what is the probability that he has brown eyes also

ii. If he has brown eyes, determine the probability that he does not have

brown hair [8+8]

2. (a) Let X denote the minimum of the two numbers that appear when a pair of

fair dice is thrown once. Determine the

i. discrete probability distribution

ii. expectation

iii. variance.

(b) Show that if p is small and n is large, then the binomial distribution B(n,p)

is approximated by the Poisson distribution. [8+8]

3. (a) If

x is a Poisson variate such that 3p (x = 4) = 1

p (x = 2) + p (x = 0) find

i. the mean of

ii. p(x

(b) Prove that the mean = mode = median for a normal distribution. [8+8]

4. A population consists of 5,10,14,18,13,24 consider all possible samples of size two

which can be drawn without replacement from the population. Find

(a) The mean of the population.

(b) The standard deviation of the population.

(d) The standard deviation of sampling distribution of means. [4

×4]

5. (a) In a random sample of 400 industrial accidents, it was found that 231 were

due atleast partially to unsafe working conditions. Construct a 99% percent

confidence interval for the corresponding true proportion?

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(b) In a study designed to investigate whether certain detonators used with ex-

plosives in coal mining meet the requirement that at least 90% will ignite

the explosive when charged, it is found that 174 of 200 detonators function

properly. Find a 95% confidence interval for the true proportion? [8+8]

6. (a) It has been suggested that an average college teacher in Andhra Pradesh

spends less than 10 hours in a week on his own academic schedule. The

figures for the time spent during a week are given below for 12 teachers.

7.1 13.1 7.8 3.6 8.4 4.9

9.6 3.4 0.1 7.2 20.3 11.1

Is the claim justified with the level of significance of 0.05?

(b) Test of the fidelity and the selectivity of 190 radio receivers produced the

results shown in the following table: [8+8]

Fidility

Low Average High

Low 6 12 32

Selectivity Average 33 61 18

High 13 15 0

7. (a) The following data pertain to the demand for a product ( in thousands of

units) and its price ( in cents) charged in five different market areas:

Price (x) 20 16 10 11 14

Demand 22 41 120 89 56

Fit a straight line of the form y =

ao + a1x to the above data

(b) Fit the model y =

axb to the following data: [8+8]

x: 1 2 3 4 5 6

y: 2.98 4.26 5.21 6.10 6.80 7.50

8. (a) The following table gives experimental values of the three variates X,Y and Z.

Fit a multiple regression of the type Z =

X + Y.

X 1 2 3 5

Y 1 3 4 2

Z 7 18 25 23

(b) The following are the marks obtained by 12 students in Economics and Sta-

tistics:

Economics(x) 78 56 36 66 25 75 82 62

Statistics(y) 84 44 51 58 60 68 62 58

Compute the Spearman rank correlation coefficient between x and y. [8+8]

? ? ? ? ?

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Code No: V0101/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

PROBABILITY AND STATISTICS

( Common to Civil Engineering, Mechanical Engineering, Chemical

Engineering, Mechatronics, Production Engineering, Bio-Technology and

Automobile Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) If P(A) = 1/2, P(B) = 1/3, P(A

\ B) = 1/5, then find

i. P(AUB)

ii. P(

Ac \ B)

iii. P(

A \ Bc)

iv. P(

Ac \ Bc)

where (

Ac = the compliment of A)

(b) Three machines produces 70%

, 20% and 10% of the total number of a factory.

The percentage of defective output of these machines are 4%

, 3% and 2%

respectively. An item is selected at random and found defective. Find the

probability that it is from

i. machine-I

ii. machine-II

iii. machine-III [8+8]

2. (a) Probability density function of a random variable X = 1/2 sin

x in 0 x

= 0 else where.

Find the mean, mode and median for the distribution and also find the prob-

ability between 0 and

(b) Two dice are thrown 5 times. If getting a double is a success. Find the

probability that getting the success

i. atleast once

ii. Two times. [8+8]

3. (a) 2% of the items of a factory are defective. The items are packed in boxes.

What is the probability that there will be

i. 2 defective items

ii. at least three defective items

(b) The marks obtained in statistics in a certain examination found to be normally

distributed. If 15% of the marks of the students

60, 40% < 30% marks,

find the mean and standard deviation. [8+8]

4. (a) A random sample of size 81 is taken from an infinite population having the

mean 65 and standard deviation 10. What is the probability that

x will be

between 66 and 68?

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Code No: V0101/R05

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(b) Write about

i. Critical region

ii. Two tailed test. [8+8]

5. (a) A lady stenographer claims that she can take dictation at the rate of 118

words per minute can we reject her claim on the basis of 100 trials in which

she demonstrates a mean of 116 words and a S.D of 15 words.

(b) In a large consignment of oranges a random sample of 64 oranges revealed

that 14 oranges were bad. If it reasonable to ensure that 20% of the oranges

are bad? [8+8]

6. The following are the average weekly losses of worker hours due to accidents in 10

industrial plants before and after a certain safety programme was put into opera-

tion:

Before: 45 73 46 124 33 57 83 34 26 17

After: 36 60 44 119 35 51 77 29 24 11

Test whether the safety programme is effective in reducing the number of accidents

at the level of significance of 0.05? [16]

7. (a) The measurements of humidity and the moisture content in a raw material

are given in the following table. Fit a Straight line of the form y = ax + b

Humidity (x) 42 35 50 43 48 62 31 36 44 39 55 48

Moisture 12 8 14 9 1 16 7 9 12 10 13 11

(b) Find the most possible values of x and y

x + 2y - 7 = 0 2x + 3y - 2 = 0

x + 8y - 3 =0 3x - y + 5 = 0. [8+8]

8. (a) The following table gives experimental values of the three variates X,Y and Z.

Fit a multiple regression of the type Z =

X + Y.

X 1 2 3 5

Y 1 3 4 2

Z 7 18 25 23

(b) The following are the marks obtained by 12 students in Economics and Sta-

tistics:

Economics(x) 78 56 36 66 25 75 82 62

Statistics(y) 84 44 51 58 60 68 62 58

Compute the Spearman rank correlation coefficient between x and y. [8+8]

? ? ? ? ?

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Code No: V0101/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

PROBABILITY AND STATISTICS

( Common to Civil Engineering, Mechanical Engineering, Chemical

Engineering, Mechatronics, Production Engineering, Bio-Technology and

Automobile Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) If A and B are any two arbitrary events of the sample space then Prove that

P( A U B) = P(A) + P(B) - P(A

\ B)

(b) A problem in statistics is given to three students A,B,C whose chances of solv-

ing it are

, 3

and 1

respectively. What is the probability that the problem

is solved.

2. (a) Define random variable, discrete probability distribution, continuous proba-

bility distribution and cumulative distribution. Give an example of each.

(b) The mean of Binomial distribution is 3 and the variance is

. Find

i. The value of n

ii. p(

x 7)

iii. p(1

x < 6). [8+8]

3. (a) A poisson distribution is such that p(x=0) = p(x=1). Find the probability

that

i. p(0

< x 3)

ii. p(1

x <4)

iii. p(x

(b) Assuming that the diameters of 1000 brass plugs taken consecutively from a

machine for a normal distribution with mean .7515 cms and S.D .002 cms.

How many plugs are likely to be rejected, if the approximated diameter is

.752

±.004. [8+8]

4. If the population is 3,6,9,15,27.

(a) List all possible samples of size 3 that can be taken without replacement from

the finite population.

(b) Calculate the mean of each of the sampling distribution of means.

5. (a) A lady stenographer claims that she can take dictation at the rate of 118

words per minute can we reject her claim on the basis of 100 trials in which

she demonstrates a mean of 116 words and a S.D of 15 words.

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Code No: V0101/R05

Set No. 4

(b) In a large consignment of oranges a random sample of 64 oranges revealed

that 14 oranges were bad. If it reasonable to ensure that 20% of the oranges

are bad? [8+8]

6. (a) Five measurements of tar content of a certain kind of cigarettes yielded 14.5,

14.2, 14.4, 14.3 and 14.6 mg per cigarettes. Show that the difference between

the mean of this sample

−

= 14.4, and the average tar claimed by the manu-

facturer

μ = 14.0, is significant at
= 0.05. Assume normality?

(b) Mechanical Engineers, testing a new arc welding technique, classified welds

both with respect to appearance and an X-ray inspection.

Quality

Bad Normal Good Total

Bad 20 7 3 30

X-ray Normal 13 51 16 80

Good 7 12 21 40

Total 40 70 40 150

Test for independence using

= 0.05 and find the individual cell contribution

to the

2 - statistic. [8+8]

7. (a) A chemical company, wishing to study the effect of extraction time on the

efficiency of an extraction operation, obtained the data shown in the following

table:

Extraction time minutes(x) 27 45 41 19 35 39 19 49 15 31

Efficiency % (y) 57 64 80 46 62 72 52 77 57 68

Fit a straight line to the given data by the method of least squares.

(b) Fit a quadratic function to the following data which gives the drying time and

the amount of additive that is intended to reduce the drying time: [8+8]

Varnish additive 0 1 2 3 4 5 6 7 8

(x in grams)

Drying time 12.0 10.5 10.0 8.0 7.0 8.0 7.5 8.5 9.0

(y in hours)

8. Use the formula

−

to compute the correlation coefficient to the

following data [16]

x: 62 56 36 66 25 75 82 78

y: 58 44 51 58 60 68 62 84

? ? ? ? ?

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Code No: T0201/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

POWER SYSTEMS-I

(Electrical & Electronic Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Draw the schematic diagram of thermal power station and also briefly discuss the

main components of the station. [16]

2. (a) Describe the fast breeder reactor.

(b) Briefly discuss the types of radiations. [10+6]

3. (a) Explain the difference between radial distribution system and ring-main dis-

tribution system.

(b) Determine the currents supplied to the ring main as shown in figure 3b from

A to B when

VA = VB and

ii.

VB = (VA + 5) volts. [8+8]

Figure 3b

4. A three-phase distribution system power is supplied at 11 kV (line voltage) and

balanced load of 50 A/phase at 0.8 lagging p.f and 70 A at 0.9 lagging p.f are taken

at Q and R respectively. The impedance of the feeders are PQ = (5+j9), QR =

(6+j10) and RP = (4+j8). Calculate the voltage at Q and R and the current

in each branch. Power factors are assumed with respect to voltage at P. [16]

5. (a) Classify various types of substations according to service requirements and

explain.

(b) Explain about various symbols used for equipments in substations. [10+6]

6. (a) Explain the effect of shunt capacitors in improving p.f.

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Code No: T0201/R05

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(b) A 3-phase synchronous motor is connected in parallel with a load of 800KW

at 0.8 p.f. lagging. The synchronous motor has a total load of 150 KW and its

excitation is so adjusted that the over all power factor becomes 0.93 lagging.

Calculate the KVA input to the motor and its power factor. Neglect motor

losses. [8+8]

7. (a) Explain the method of constructing a load duration curve, and load curve.

(b) A residential consumer has a connected load of 10 lamps each of 100W at his

premises. His demand is as follows: from mid night to 5AM, 100W; from 5AM

to 6PM, no load; from 6 PM to 7PM, 800W; from 7PM to 9PM, 900W; from

9 PM to mid night, 400W.

i. Plot the load curve

ii. find the energy consumption during 24 hours and

iii. calculate the demand factor, average load, maximum demand and load

factor. [8+8]

8. (a) What is the difference between flat rate tariff and block rate tariff.

(b) Obtain a two part tariff for the consumers of a supply undertaking which

generates 390

×106 KWh per annum and has a maximum demand of 130MW

connected to it. The cost is distributed as follows:

Fuel Rs. 5

× 106, generation Rs. 2.4 × 106, transmission Rs. 5 × 106 and

distribution Rs. 3

.4 × 106, of these items 90%, 10%, 5% and 7% respectively

are allocated to running costs, the remainder being a fixed charge. The total

loss between the station and the consumers is 10% of the generated energy. If

the load factor of the station is raised to 40% for the same maximum demand,

find the percentage saving in the overall cost per KWh. [8+8]

? ? ? ? ?

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Code No: T0201/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

POWER SYSTEMS-I

(Electrical & Electronic Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Explain the following:

(a) Economizer

(b) Feed water heater. [8+8]

2. (a) What are the functions of moderator and control rods in a nuclear power

plants.

(b) Distinguish between thermal and fast reactors. Classify each according to

moderator, coolant and fuel utilized. [8+8]

3. (a) What are the different types of distributor.

(b) A distributor has a length of 800m and is loaded as shown in figure 3. The

ends X and Y are maintained at 220V and 225V respectively. If the mini-

mum voltage allowed at consumers end is 215V, find out the diameter of the

conductor. The resistivity of the conductor is 1.72

μ -cm. [10+6]

Figure 3

4. A 3-phase system is supplied at 6.6 kV at terminal ‘A’ as shown in figure 4. The

load is balanced and the p.f. are lagging, calculate load current in each branch.

[16]

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Code No: T0201/R05

Set No. 2

Figure 4

5. (a) Explain the 3-phase GIS with circuit diagram.

(b) Contrast between air insulated substations and gas insulated substations.

[10+6]

6. (a) What do you understand by power factor? Explain the necessity of improving

power factor.

(b) A consumer takes a steady load of 300 KW at a lagging p.f. of 0.7 for 3,000

hours a year. The tariff is Rs. 1,300 per KVA of maximum demand per annum

plus Rs. 0.8 per KWh. The annual cost of the phase advancing is Rs. 130 per

KVAR. Determine the annual saving if the p.f. of the load is improved. [8+8]

7. (a) Explain the load curve and factors that can deduced from the curve

(b) The annual load duration curve of a certain power station can be considered

as a straight line from 20MW to 4MW. To meet this load, three turbine-

generator units, two rated at 10 MWeach and one rated at 5MWare installed.

Determine

i. installed capacity

ii. plant factor

iii. units generated per annum and

iv. utilization factor. [8+8]

8. (a) Describe some of the important types of tariff commonly used.

(b) A power station has an installed capacity of 20,00 kW. The cost of the station

is Rs. 1,200 / kW. The fixed cost is 13% of the cost of investment. On full

load at 100% load factor, the variable costs of the station per year are 1.5

times the fixed costs. Assume that there is no reserve capacity of the plant

and that the variable costs are proportional to energy production. Find the

cost of generation per kWh at load factors of 100% and 20%. [8+8]

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Set No. 2

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Code No: T0201/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

POWER SYSTEMS-I

(Electrical & Electronic Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Describe the schematic arrangement of a thermal power station and explain the

function of each component briefly. [16]

2. (a) Describe the boiling water reactor.

(b) What are the factors to be considered for selecting the location of site for

nuclear power plant? [10+6]

3. (a) What is an inter connector? Discuss its advantages in distribution system.

(b) A 300 m distributor fed from both ends

F1 and F2 is loaded uniformly at the

rate of 2 A/m run. The resistance of loop is 0.2 /km. Find the minimum

voltage and the point where it occurs, if the feeding points F

1 and F2 are

maintained at 225 V and 220 V respectively. Also find the currents supplied

from the feeding points

F1 and F2. [8+8]

4. (a) What is the importance of load p.f. in AC distribution?

(b) The loading on a distributor is shown in figure 4b. The distributor is a two

core cable for which the resistance and reactance are 0.25 and 0.125 per

Km of cable run respectively. What should be the voltage at the point A to

maintain 400V at point D. [8+8]

Figure 4b

5. What are the functions of a substation? What are the different types of substations?

Write short notes on each of them. [16]

6. (a) State whether the tap changes in transformer is provided on HV side or LV

side? Explain the reason for its location and elaborate how lowering or raising

the output voltage is actually done.

(b) It is provided to control the voltage of a 3-phase, 3.3 MVA feeder varying

between 3 KV and 3.5 KV about 3.3 KV. Determine the minimum turn ratio

of the regulator. Find also its rating. [8+8]

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Code No: T0201/R05

Set No. 3

7. (a) Discuss the role of load factor on the cost of electrical energy.

(b) From a load duration curve, the following data are available: the maximum

demand on the system is 25 MW. The load supplied by two units is 15 MW

and 12.5 MW. Unit no.1 acts as a base load unit and No.2 as a peak load

unit. The base load unit works for 100% of the time and peak load unit for

only 40% of time the energy generated by unit No.1 is 1

×108 units and that

by No.2 is 1

×107 units. Determine the load factor, plant capacity factor and

plant use factor of each unit and load factor of the total plant. [6+10]

8. (a) Discuss the different classifications of costs of electrical energy.

(b) A power station has an installed capacity of 50MW and it costs Rs. 1000 Per

KW. The annual fixed cost is 15% of the capital cost and at 100% load factor,

the variable cost per year is 1.3 times the fixed cost. Assuming that there is

no reserve capacity, determine the cost of generation per KWh at load factor

25%, 50%, 75%, 90% and 100%. Comment on the results. [8+8]

? ? ? ? ?

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Code No: T0201/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

POWER SYSTEMS-I

(Electrical & Electronic Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Draw the complete schematic diagram of a coal fired thermal power plant. Label

each component. Discuss briefly the function of each component. [16]

2. (a) What is the need of nuclear power generation?

(b) What are the merits and demerits of nuclear power plant? [6+10]

3. (a) Prove that the total voltage drop in a uniformly loaded distributor fed at

one end only is equal to the drop produced by the whole load assumed to be

concentrated at the mid point of the distributor

(b) A 2-wire DC street mains AB, 600m long is fed from both ends at 220V, loads

of 20A, 40A, 50A and 30A are tapped at distances of 100m, 250m, 400m and

500m from the end A respectively. If the area of cross section of distributor

conductor is 1

, find the minimum consumer voltage. Take = 1.7 μ-cm.

[8+8]

4. A single phase line (ABC) of length 2 Km having resistance and reactance (go and

return) as 0.06 and 0.1 ohms / Km. A is the feeding point, B is the mid point of

the line taking a load of 100A at 0.9 p.f. leads and C is the far end taking a load

of 120 A at UPF. The voltage at the ‘C’ is 230V. Find the voltage at the sending

end and the phase angle difference between the voltages of two ends. If

(a) power factors of the loads are with reference to far end voltage

(b) Power factors of the loads are with reference to the voltages at the load points.

[8+8]

5. (a) Explain key diagram of a substation with suitable diagram.

(b) Distinguish between single bus system with and with out sectionalization.

[8+8]

6. (a) What factors determine the economical limit of p.f. correction? Show that

the economical limit to which the p.f. of a lagging p.f. load can be raised is

independent of the original value of the p.f. if the tariff consists of a fixed

charge per KVA of maximum demand plus a flat rate per KWh.

(b) Calculate the value of the new p.f. when the tariff is Rs. 1,350 per KVA of

maximum demand plus a flat rate paise 80 per kWh. Assume additional cost

of condensers etc. at Rs. 1,050 per KVA of such plant. Rate of interest and

depreciation together is taken as 10%. [8+8]

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Code No: T0201/R05

Set No. 4

7. (a) Explain the load curve and factors that can deduced from the curve

(b) The annual load duration curve of a certain power station can be considered

as a straight line from 20MW to 4MW. To meet this load, three turbine-

generator units, two rated at 10 MWeach and one rated at 5MWare installed.

Determine

i. installed capacity

ii. plant factor

iii. units generated per annum and

iv. utilization factor. [8+8]

8. (a) What are the factors influencing the formulation of tariff.

(b) Daily load of an industry is 200kW for first 1 hour, 150 kW for next 7 hours,

50 kW for next 8 hours and 1 kW for the remaining time. If the tariff in force

is Rs. 1,000 per KW of maximum demand per annum plus Rs. 2.25 per KWh,

find the electricity expenditure per year. [8+8]

? ? ? ? ?

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Code No: V0401/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

ELECTRICAL TECHNOLOGY

( Common to Electronics & Communication Engineering and Electronics &

Telematics)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Explain O.C.C. of a D.C. shunt generator.

(b) A separately exited generator gave the following data for o.c.c. at 1000 r.p.m.

f in Amps 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

g in Volts 5 50 100 140 170 190 200 205

The armature resistance including brushes is 0.5 . If the generator is now

shunt connected and is driven at 1100 r.p.m., then, for a total shunt field

resistance of 180.

i. Calculate the no load e.m.f.

ii. Calculate the output current and the shunt field current for the terminal

voltage of 190V. [8+8]

2. (a) Explain the construction and working principle of D.C. motor?

(b) A series motor has a resistance of 1 between its terminals. The motor runs

at 800 r.p.m. at 200V taking a current of 15A. Calculate the speed at which

the motor will run when connected in series with a 5 resistance and taking

the same current at the same supply voltage. [10+6]

3. Draw the phasor diagrams of a transformer at no load and full load lagging power

factor conditions and explain the operation of a transformer. [16]

4. What are the different losses occurring in a transformer. How can these losses be

determined experimentally. [16]

5. (a) Explain why a starter is necessary for starting of 3-phase Induction Motor?

Name the starters used for starting 3-phase Induction Motor.

(b) The power input to rotor of a 440V, 50Hz, 3-phase, 12-pole Induction Motor

is 75W. The rotor e.m.f has a frequency of 2Hz. Calculate

i. Slip

ii. rotor speed

iii. rotor copper loss

iv. mechanical power developed [8+8]

6. (a) Derive Pitch and Distribution factors used in the design of armature winding

of alternator.

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Code No: V0401/R05

Set No. 1

(b) A 3-phase, 16-pole alternator has the following data: Number of slots = 192;

Conductors / slot = 8 (conductors of each phase are connected in series); coil

span = 160

0(electrical); Calculate the pitch and distribution factors. [8+8]

7. Explain the principle operation of a shaded pole single phase induction motor and

draw its torque speed characteristic. [16]

8. With a neat sketch explain in detail moving iron repulsion type instrument [16]

? ? ? ? ?

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Code No: V0401/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

ELECTRICAL TECHNOLOGY

( Common to Electronics & Communication Engineering and Electronics &

Telematics)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Sketch the Magnetization and Load characteristics of a D.C. shunt Generator?

Explain them

(b) The open circuit characteristics of a separately excited generator at 650 r.p.m.

is as under:

f in Amps 1.6 3.2 4.8 6.4 8.0 9.6 11.2

G in Volts 148 285 390 460 520 560 590

For this generator, obtain

i. The voltage to which the machine will excite as a shunt generator with a

field resistance of 60.

ii. The critical value of the shunt field resistance at this speed. [8+8]

2. (a) Derive the expression of back emf in a D.C. motor and briefly describe its role

in starting and running of motor?

(b) A 250V DC shunt motor has an armature resistance of 0.5 and a field resis-

tance of 250 . When driving a constant torque load at 600rpm, the motor

draws 21A. What will be the new speed of the motor if an additional 250

resistance is inserted in the field circuit? [8+8]

3. (a) What is an ideal transformer Draw its no load phasor diagram

(b) The primary winding of a 50 HZ single phase transformer has 480 turns and

is fed from 6400 V supply The secondary winding has 20 turns. Find the peak

value of flux in the core and the secondary Voltage. [8+8]

4. (a) Determine the efficiency of a 150 KVA transformer at 50% full load and 0.8

power factor lag if the copper loss at full load is 1600 Watts and iron loss is

1400 Watts.

(b) Draw the no load and full load phasor diagrams of a transformer. [8+8]

5. (a) Show that when a 3-phase supply is given to the stator winding of Induc-

tion Motor, it produces a rotating magnetic field of constant magnitude and

rotating at synchronous speed.

(b) A 12-pole, 3-phase Induction Motor is fed from 100Hz supply. If the frequency

of rotor e.m.f at full load is 5 Hz, find the Full-Load speed and %Slip. [12+4]

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6. (a) Explain the tests to be conducted for predetermining the regulation of alter-

nator.

(b) A 3.3KV, 3-phase star-connected alternate has a full load current of 100A. On

short-circuit a field current of 5 amperes was necessary to produce full-load

current. The e.m.f. on open-circuit for the same excitation was 900 volts.

The armature resistance was 0.8 /phase. Determine the full-load voltage

regulation for 0.8 leading p.f. load. [8+8]

7. Explain the principle operation of a shaded pole single phase induction motor and

draw its torque speed characteristic. [16]

8. With a neat sketch explain in detail moving iron repulsion type instrument [16]

? ? ? ? ?

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Code No: V0401/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

ELECTRICAL TECHNOLOGY

( Common to Electronics & Communication Engineering and Electronics &

Telematics)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Discuss the internal and external characteristics of a D.C. shunt generator.

(b) A Separately excited generator, when running at 1200rpm supplies 200A at

125V to a circuit of constant resistance. What will be the current when

the speed is dropped to 1000rpm if the field current is unaltered? Armature

resistance is 0.04. Total drop at brushes is 2V. Ignore change in armature

reaction. [10+6]

2. (a) A D.C. shunt motor fails to start. What may be the probable faults to start?

(b) A 200V shunt motor develops 23hp when taking 20.2 kW. The field resistance

is 50 and the armature resistance 0.06. What is the efficiency and the

power input when the output is 16hp? [6+10]

3. With neat diagram discuss the principle of working of a transformer. [16]

4. (a) State and prove the condition for maximum efficiency of a transformer.

(b) A 30 KVA single phase transformer has an iron loss of 457 watts and copper

loss of 125 watts when delivering half the full load. At what percentage of full

load will the transformer have maximum efficiency. [8+8]

5. (a) Derive the expression for Torque-Slip characteristics of a 3-phase Induction

Motor. Explain how the torque of Induction Motor varies with speed with the

help of a diagram.

(b) Deduce the condition for maximum torque of a 3-phase Induction Motor.

of rotor e.m.f at Half full-load is 2 Hz, find the Half Full-load speed and %Slip.

[8+4+4]

6. (a) Explain the constructional features of alternator.

(b) How e.m.f is induced in an 3-phase alternator? Derive the expression for e.m.f

induced in an alternator in terms of pitch and distribution factors. [8+8]

7. Explain with neat diagrams the principle of operation of

(a) AC servo motor

(b) Stepper motor. [8+8]

8. With a neat sketch explain in detail moving iron attraction type instrument [16]

? ? ? ? ?

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Code No: V0401/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

ELECTRICAL TECHNOLOGY

( Common to Electronics & Communication Engineering and Electronics &

Telematics)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Explain the constructional features of a D.C. Machine with the help of a neat

sketch.

(b) Name the main parts of a D.C. Machine and state the materials of which each

part is made.

grams. [8+4+4]

2. Draw the characteristic curves of DC shunt and series motors. Use these curves to

explain the applications for which these motors were used. [16]

3. Explain the working of a transformer at no load and full load conditions with neat

diagrams. [16]

4. (a) Determine the efficiency of a 150 KVA transformer at 50% full load and 0.8

power factor lag if the copper loss at full load is 1600 Watts and iron loss is

1400 Watts.

(b) Draw the no load and full load phasor diagrams of a transformer. [8+8]

5. (a) Explain why a starter is necessary for starting of 3-phase Induction Motor?

Name the starters used for starting of 3-phase.

i. Wound Rotor Induction Motor

ii. Squirrel Cage Induction Motor

(b) A 3-phase, 50Hz, 12-pole Squirrel Cage Induction Motor has a short circuit

current equal to 4 times the full-load current and has full-load speed of 480

rpm. Find the starting torque as a percentage of full-load torque if the motor

is started by

i. DOL starter

ii. Star-Delta starter [8+8]

6. (a) Explain the constructional features of alternator.

(b) How e.m.f is induced in an 3-phase alternator? Derive the expression for e.m.f

induced in an alternator in terms of pitch and distribution factors. [8+8]

7. Show that a single phase winding when excited by a single phase supply produce

two equal and opposite revolving fields. [16]

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8. (a) Discuss the classification of electrical instruments.

(b) Explain the significance of controlling torque and damping torque relevant to

the operation of indicating instruments. [8+8]

? ? ? ? ?

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Code No: V0501/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

SOFTWARE ENGINEERING

( Common to Computer Science & Engineering, Information Technology

and Computer Science & Systems Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Suggest three specialized software tools which might be developed to support a

Process improvement programme in an organization. [16]

2. (a) What is system requirements? How would you specify them?

(b) What is non-functional requirements? Explain the classification of different

types of it ? [3+3+4+6]

3. What is ethnography? Explain why and where it is used in software engineering?

[4+12]

4. (a) What is software architecture? Discuss how it’s components are derived.

(b) Give an overall architectural structure for Safe Home system with top-level

components. [3+5+8]

5. (a) Using the UML graphical notation for object classes, design a Telephone object

classes, identify the attributes and operations.

(b) What is a Package? Give one example. [12+4]

6. What is meant by System testing? Discuss the various types of system tests that

are worthwhile for software-based systems. [16]

7. (a) Distinguish between metrics and measurements.

(b) What is meant by software process and project metrics? [6+10]

8. (a) What is six sigma? What are the core steps of the six sigma methodology?

(b) What is meant by software availability? Discuss the measures of it. [10+6]

? ? ? ? ?

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Code No: V0501/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

SOFTWARE ENGINEERING

( Common to Computer Science & Engineering, Information Technology

and Computer Science & Systems Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Elaborate on evolution of software. [16]

2. (a) Discuss about Concurrent development model. Explain how it is different

from incremental model.

(b) Explain the merits and demerits of Component assembly model. [5+5+6]

3. Discuss the statement, “ Ethnographic studies can reveal critical process details

which are often missed by other requirement elicitation techniques”. [16]

4. Discuss in detail how would you transform analysis model into design model. [16]

5. (a) Discuss about UID tools.

(b) With a neat diagram explain the interface design evaluation cycle. [6+10]

6. (a) What is meant by software quality? Discuss clearly the McCall‘s software

quality factors.

(b) Discuss about ISO 9126 Quality factors. [10+6]

7. (a) Present an argument against lines of code as a measure for software pro-

ductivity. Will your case hold up when dozens or hundreds of projects are

considered?

(b) The software used to control a photocopier requires 32,000 lines of C and 4200

lines of Small talk. Estimate the number of function points for the software

inside the copier. [8+8]

8. Discuss in detail about Formal Technical Reviews(FTR). [16]

? ? ? ? ?

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Code No: V0501/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

SOFTWARE ENGINEERING

( Common to Computer Science & Engineering, Information Technology

and Computer Science & Systems Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. What is software process assessment? Describe it?s purpose. Why SPICE has been

developed as a standard for software process assessment. [3+3+10]

2. (a) Define user and system requirements. Differentiate between them.

(b) What is requirements specification? Who are the readers of different types of

requirements specification? [4+2+3+7]

3. (a) Discuss how information is collected in VORD.

(b) Explain the application of VORD for bank ATM. [6+10]

4. Discuss about various software design concepts. Explain the role of each design

concept. [8+8]

5. (a) what is an Object? Explain with an example how objects are identified by

grammatical parsing?

(b) Object-Oriented systems are easier to change than systems developed using

other approaches. Discuss. [8+8]

6. (a) What is meant by Basis path testing? Discuss the steps which can be applied

to derive the basis set.

(b) What is a graph matrix? How do we extend graph matrix for use in testing?

[8+8]

7. (a) With a sample risk information sheet, explain the RMMM plan.

(b) Discuss about software tools for risk management. [10+6]

8. (a) What is meant by software quality measurement? What are the things that

are covered in SQA?

(b) Discuss the importance of quality assurance. [10+6]

? ? ? ? ?

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Code No: V0501/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

SOFTWARE ENGINEERING

( Common to Computer Science & Engineering, Information Technology

and Computer Science & Systems Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. What is software process assessment? Describe it?s purpose. Why SPICE has been

developed as a standard for software process assessment. [3+3+10]

2. Recommend the development process models for the following softwares.

(a) Production planning and control in a machine shop.

(b) Testing tool. [8+8]

3. (a) Define ethnography. Explain why it is combined with prototyping for require-

ment analysis.

(b) Differentiate between formal and informal requirements review. [10+6]

4. (a) Discuss the measures used for assessing functional independence.

(b) Elaborate on refinement. Give an illustrative example for it. [6+4+6]

5. (a) Discuss about task elaboration and object elaboration in user interface design.

(b) What is a swim lane diagram? Explain with one example. [8+8]

6. (a) Discuss clearly the Unit test procedures and environment.

(b) What is Integration testing? Discuss about depth-first integration. [8+8]

7. (a) Compare the reactive and proactive risk management strategies.

(b) What types of risks are we likely encounter as software is built? [6+10]

8. Quality and reliability are related concepts, but are fundamentally different in a

number of ways. Discuss them. [16]

? ? ? ? ?

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Code No: T1001/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

CALIBRATION AND ELECTRONIC MEASUREMENTS

(Electronics & Instrumentation Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. What is meant by error and mention different types of errors? [16]

2. (a) Write short notes on the following terms:

i. International ohms

ii. International amperes

iii. Absolute units

iv. Universal time.

(b) State the SI units, unit symbols and define each unit for the following

i. Magnetic flux

ii. Resistance

iii. Inductance

iv. Capacitance. [8+8]

3. (a) Write short notes on measurement reliability?

(b) What do you understand by testing, where is it performed and give the appli-

cations of testing? [8+8]

4. (a) Write short notes on measurement of very large current by thermocouple

method?

(b) With a neat block diagram explain the microprocessor based ramp type DVM?

[8+8]

5. (a) Discuss the problems associated in AC bridges if used for measurement at very

high frequencies.

(b) A Hay bridge is used to measure an inductive impedance.The bridge constants

at balance are C1=0.1

μF, R1= 20K, R2= 5K R3= 2K and W=3000

rad/s. Calculate Lx, Rx. [8+8]

6. (a) What is the function of a gate control Flip-Flop in a frequency counter? Ex-

plain its operation.

(b) Explain how do you interface the seven-segment display to a counter.[2+6+8]

7. (a) Describe the electrostatic focusing system of a CRT.

(b) What is the minimum distance L, that will allow full deflection of 4 cm at the

oscilloscope screen with a deflection factor of 100 V/cm and with an acceler-

ating potential of 2000 V ? [8+8]

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8. (a) Draw and discuss the spectral displays of various modulations using spectrum

analyzer.

(b) Explain the F M method of magnetic tape recording and explain its advantages

and disadvantages. [8+6+2]

? ? ? ? ?

2 of 2

Code No: T1001/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

CALIBRATION AND ELECTRONIC MEASUREMENTS

(Electronics & Instrumentation Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. Ten measurements of the resistance of a resistor gave 101.2, 101.7, 101.3,

101.0, 101.5, 101.3, 101.2, 101.4, 101.3 and 101.1. Assume that only

random errors are present. Calculate

(a) the arithmetic mean

(b) the deviation from the mean

(d) Standard deviation

(e) Variance

(f) Probable error [16]

2. What is S.I system of units? Define the fundamental standards of this system [16]

3. (a) What are the necessary steps taken before performing calibration?

(b) What is meant by testing, where is it performed and give the applications of

testing?

4. (a) A dual slope integrating type A/D converter has an integrating capacitor of

0.01

μf and a resistance of 10 K. If the reference voltage is 2V and output of

an integrating is not to exceed 10V what is the max time the reference voltage

can be integrated?

(b) Explain the performance characteristics of DVM‘s? [8+8]

5. (a) “ The Maxwell’s bridge is used for the measurement of medium. Q coils only”

Justify this statement with suitable examples.

(b) Draw a basic Q meter circuit and discuss how does it measure Q by direct

connection method. [6+10]

6. (a) With the help of a block diagram explain the multiplexed display technique

used in a frequency counter.

(b) Explain in detail about frequency mode errors and period mode errors. [4+6+6]

7. (a) Describe the electrostatic focusing system of a CRT.

(b) What is the minimum distance L, that will allow full deflection of 4 cm at the

oscilloscope screen with a deflection factor of 100 V/cm and with an acceler-

ating potential of 2000 V ? [8+8]

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Code No: T1001/R05

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8. (a) Draw the block diagram of a filter bank spectrum analyzer and explain its

operation.

(b) Write short notes on display systems. [3+5+8]

? ? ? ? ?

2 of 2

Code No: T1001/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

CALIBRATION AND ELECTRONIC MEASUREMENTS

(Electronics & Instrumentation Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. A set of independent measurements were made to determine the weight of a lead

shot. The weights in grams were 1.570, 1.597, 1.591, 1.562, 1.577, 1.580, 1.564,

1.586, 1.550, 1.575

Calculate

(a) the arithmetic mean

(b) the deviation from the mean

(d) Standard deviation

(e) Variance

(f) Probable error of one reading

(g) Probable error of mean. [16]

2. (a) Describe the international standard of mass, length and volume?

(b) What are atomic standards for frequency and time? [8+8]

3. (a) Explain the following terms

i. Measurement and test equipment

ii. Traceability

iii. Reliability

iv. Tolerance limits

(b) Explain the procedure that should be followed before attempting to calibrate

deflecting instruments? [8+8]

4. (a) Explain the successive approximation type DVM?

(b) Distinguish between series and shunt type ohmmeter from the dial calibration?

How can you estimate the internal resistance of an ohmmeter from its dial?

[8+8]

5. (a) Explain the differences in balancing DC and AC bridges .

(b) An unbalanced bridge is given in figure 1. The galvanometer has a current

sensitivity of 10 mm/

μ A and an internal resistance of 200 calculate the

deflection of the galvanometer. [8+8]

6. (a) What is zero crossing detector? How can it be used to measure the frequency?

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Code No: T1001/R05

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Figure 1:

(b) Explain how to extend the frequency range of a frequency counter using het-

erodyne frequency converter? [3+5+8]

7. Write short notes on the following controls.

(a) Delayed Sweep

(b) ALT/ CHOP mode

8. (a) With a neat sketch explain the operation of a strip chart recorder.

(b) Explain different applications of spectrum analyzer. [2+6+8]

? ? ? ? ?

2 of 2

Code No: T1001/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

CALIBRATION AND ELECTRONIC MEASUREMENTS

(Electronics & Instrumentation Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. The following 10 observations were recorded when measuring a voltage:

41.7, 42.0, 41.8, 42.0, 42.1, 41.9, 42.0, 41.9, 42.5 and 41.8 volt Calculate

(a) the arithmetic mean

(b) the deviation from the mean

(d) Standard deviation

(e) Variance

(f) Probable error of one reading

(g) Probable error of mean

(h) Range. [16]

2. (a) What are the differences between International and absolute standards?

(b) Describe the international standard of length and volume?

3. Write short notes on any of the

THREE:

(a) Testing

(b) Calibration

(d) Traceability. [16]

4. (a) Draw the circuit of AC voltmeter using full wave & half wave rectifier and

explain its working? What are the advantages of using full wave rectifier over

half wave rectifier while measuring AC voltage?

(b) Give the general specifications of DVM‘s? [12+4]

5. (a) Explain how a Kelvin’s double bridge can accurately measure low resistances.

Also derive the condition for balance.

(b) In the Kelvin’s Bridge shown in figure 1 the ratio of Ra to Rb is 2000,R1 is

10 and R1=0.2 R2. Calculate the value of Rx . [10+6]

6. (a) What is the function of a gate control Flip-Flop in a frequency counter? Ex-

plain its operation.

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Code No: T1001/R05

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Figure 1:

(b) Explain how do you interface the seven-segment display to a counter.[2+6+8]

7. (a) Name the various types of probes with their applications

(b) Write short notes on time base generators used in oscilloscopes [8+8]

8. (a) With a neat sketch explain the operation of Magnetic recorder . [8]

(b) Explain the operating principles of LCD display. [8]

? ? ? ? ?

2 of 2

Code No: V1101/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

PULSE AND DIGITAL CIRCUITS

( Common to Bio-Medical Engineering, Electronics & Control Engineering,

Electronics & Computer Engineering and Instrumentation & Control

Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) A symmetrical square wave is applied to a HP circuit having R = 20 k and

C = 0.05

μ f. If the frequency of input signal is 1kHz and the signal swings

0.5V, draw the output wave shape and indicate the voltages.

(b) What happens if the signal frequency of the signal is reduced to 100 Hz? Show

output curve. [8+8]

2. (a) Explain transfer characteristics of the emitter coupled clipper and derive the

necessary equations.

(b) Draw the basic circuit diagram of positive peak clamper circuit and explain

its operation. [8+8]

3. (a) Explain the terms pertaining to transistor switching characteristics.

i. Rise time.

ii. Delay time.

iii. Turn-on time.

iv. Storage time.

v. Fall time.

vi. Turn-off time.

(b) Give the expression for risetime and falltime in terms of transistor parameters

and operating currents. [6+10]

4. (a) Explain different triggering methods of binary circuits.

(b) A collector coupled Fixed bias binary uses NPN transistors with

hFE = 100.

The circuit parameters are

VCC = 12v, VBB = -3v, RC = 1k , R1 = 5k ,

and

R2 = 10 k . Verify that when one transistor is cut-off the other is in

saturation. Find the stable state currents and voltages for the circuit. Assume

for transistors

VCE(sat) = 0.3V and VBE(sat) = 0.7V. [8+8]

5. (a) Compare the voltage and current time base generators with some examples.

(b) What are the reasons for non linearity of sweep in current time base genera-

tors? Explain how to rectify this? [8+8]

6. (a) Explain with some example how a negative resistance devices used as relax-

ation oscillator which is used for synchronization?

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Code No: V1101/R05

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(b) Explain how the symmetrical signals are used to synchronize a sweep circuit?

[8+8]

7. (a) Draw and explain a sampling diode whose response is not sensitive to the

upper level of the control voltage.

(b) Draw and explain a unidirectional gate which delivers an output only at a

coincidence of a number of control voltages. [8+8]

8. (a) What are the basic logic gates which perform almost all the operations in

Digital communication systems.

(b) Give some applications of logic gates.

(d) Draw a pulse train representing a 11010111 in a synchronous positive logic

digital system. [4+4+4+4]

? ? ? ? ?

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Code No: V1101/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

PULSE AND DIGITAL CIRCUITS

( Common to Bio-Medical Engineering, Electronics & Control Engineering,

Electronics & Computer Engineering and Instrumentation & Control

Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) What is meant by linear wave shaping.

(b) In an RC low pass circuit R=2k and C=1

μ F A square with half period of

μ Sec. is applied as input to this circuit. Determine the output waveform.

2. (a) Determine

Vo for the network shown in figure 2a for the given waveform.

Assume ideal Diodes.

Figure 2a

(b) Draw the basic circuit diagram of positive peak clamper circuit and explain

its operation. [8+8]

3. Explain the following:

(a) Storage and transition times of the diode as a switch.

(b) The behaviour of the transistor switch in saturation. [8+8]

4. (a) Consider the symmetrical emitter triggering circuit of the figure 4 with Rc=3Re,

1=2R2, and VCC=6V. Indicate all the circuit voltages in the quiescent state

and indicate also the voltages immediately after a 5-V positive step is applied.

Assume that D3 and D4 are always in the breakdown region and that either

D1 or D2 but not both in the breakdown region.

(b) Repeat part (a) for a 25-V step. What limits the maximum size of the input

step? What limits the minimum size of the input step? [16]

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Code No: V1101/R05

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Figure 4

5. (a) What is a Linear time base generator? Give its Applications

(b) Write the differences between the voltage and current time base generators?

6. (a) Why synchronization is required in digital systems? What are the different

types of synchronization? Give some examples.

(b) Explain the pulse synchronization of a sweep generator using UJT with the

help of neat circuit diagram. [8+8]

7. (a) What is pedestal? Draw and explain the sampling gate which cancel the

pedestal.

(b) What are the applications a sampling gates? Explain any one application in

detail. [8+8]

8. (a) With the help of circuit diagram explain the purpose of clamping diode in a

positive diode AND gate.

(b) Explain the effect of and diode capacitance on the output pulse of diode AND

gate. [8+8]

? ? ? ? ?

2 of 2

Code No: V1101/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

PULSE AND DIGITAL CIRCUITS

( Common to Bio-Medical Engineering, Electronics & Control Engineering,

Electronics & Computer Engineering and Instrumentation & Control

Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Prove that an RC circuit behaves as a reasonably good integrator if RC

> 15T,

Where T is the period of an input ‘

Em sin !t’.

(b) What is the ratio of the rise time of the three sections in cascade to the rise

time of Single section of low pass RC circuit. [8+8]

2. (a) For the circuit shown in figure 2a ,

Vi is a sinusoidal voltage of peak 100

volts. Assume ideal diodes. Sketch one cycle of output voltage. Determine

the maximum diode Current.

Figure 2a

(b) Explain positive peak clipping with reference voltage. [12+4]

3. Write Short notes on:

(a) Diode switching times

(b) Switching characteristics of transistors

4. Regeneration is possible in the fixed-bias transistor flip-flop if the base-to-base

voltage gain exceeds unity. Verify that this gain condition is satisfied provided that

feRc > R1. Assume that for each stage the current gain is |AI | = hFE 　 1 and

that the input resistance R

i is small compared with either R1 or R2. [16]

5. (a) With the help of a neat circuit diagram and waveforms explain the working

of a Transistor current sweep circuit.

(b) A Bootstrap sweep generator is shown in Figure 5 Transistor

Q1 are of silicon

with

hfe(min) =30. VCE(sat) = 0.4V and VBE(sat) = 0.8V. Assume a voltage

drop of 0.5V across the forward biased diode D. Calculate all the quiescent

1 of 2

Code No: V1101/R05

Set No. 3

state voltages and currents. If a periodic gating signal with a frequency of

1 kHz and Tg=0.5ms is applied, determine the sweep time, sweep amplitude

and sweep frequency. [8+8]

Figure 5

6. (a) Explain the factors which influence the stability of a relaxation divider with

the help of a neat waveforms.

(b) A UJT sweep operates with Vv = 3V, Vp=16V and

=0.5. A sinusoidal

synchronizing voltage of 2V peak is applied between bases and the natural

frequency of the sweep is 1kHz, over what range of sync signal frequency will

the sweep remain in 1:1 synchronism with the sync signal? [8+8]

7. (a) With the help of a neat diagram, explain the working of two-diode sampling

gate.

(b) Derive expressions for gain and minimum control voltages of a bi-directional

two- diode sampling gate. [8+8]

8. (a) Draw and explain the circuit diagram of integrated positive DTL NOR gate

(b) Give the IEEE standard, Boolean expression and truth table for a two input

NOR and NAND gates. [8+8]

? ? ? ? ?

2 of 2

Code No: V1101/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

PULSE AND DIGITAL CIRCUITS

( Common to Bio-Medical Engineering, Electronics & Control Engineering,

Electronics & Computer Engineering and Instrumentation & Control

Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) What is the function of a comparator? Explain its operation.

(b) Explain the response of a low pass circuit to an exponential input is applied.

2. (a) Draw the basic circuit diagram of a DC restorer circuit and explain its oper-

ation. Sketch the out put wave form for a sinusoidal input.

(b) Draw the basic circuit diagram of positive peak clamper circuit and explain

its operation. [8+8]

3. Write Short notes on:

(a) Diode switching times

(b) Switching characteristics of transistors

4. (a) Explain the working of a Bistable multivibrator circuit with the help of neat

waveforms. What are its applications?

(b) Design a collector coupled one-shot multivibrator circuit using n-p-n transis-

tors. Neglect

ICBO. Assume VCE(sat) to be 0v., hFE(min) = 20. In the stable

state, the OFF transistor has

VBE = -1v. The on transistor has base current

IB which is 50% in area of the

IB(min) value. Vcc = 6v, IC(sat) = 2 mA. Delay

time is 3000

μsec. Choose R1 = R2. [8+8]

5. (a) How are linearly varying current waveforms generated?

(b) In the boot strap circuit shown in figure5

Vcc = 25 V, VEE = -15 V, R = 10 K

ohms,

RB = 150 K ohms, C = 0.05 μF. The gating waveform has a duration

of 300

μs. The transistor parameters are hie = 1.1Kohms, hre = 2.5 x 10−4 K

ohms

hfe =50 hoe = 1/40K ohms.

i. Draw the waveform of IC1 and Vo , labeling all current and voltage levels,

ii. What is the slope error of the sweep?

iii. What is the sweep speed and the maximum value of the sweep voltage?

iv. What is the retrace time Tr for C to discharge completely?

v. Calculate the recovery time T1 for C1 to recharge completely. [6+10]

1 of 2

Code No: V1101/R05

Set No. 4

Figure 5

6. (a) Explain the factors which influence the stability of a relaxation divider with

the help of a neat waveforms.

(b) A UJT sweep operates with Vv = 3V, Vp=16V and

=0.5. A sinusoidal

synchronizing voltage of 2V peak is applied between bases and the natural

frequency of the sweep is 1kHz, over what range of sync signal frequency will

the sweep remain in 1:1 synchronism with the sync signal? [8+8]

7. (a) Why are sampling gates called linear gates?

(b) What are the other names of a gate signal?

8. (a) What are the basic logic gates which perform almost all the operations in

Digital communication systems.

(b) Give some applications of logic gates.

(d) Draw a pulse train representing a 11010111 in a synchronous positive logic

digital system. [4+4+4+4]

? ? ? ? ?

2 of 2

Code No: T2101/R05

Set No. 1

II B.Tech II Semester Supplementary Examinations, December 2009

MATHEMATICS FOR AEROSPACE ENGINEERS

(Aeronautical Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Define Gamma function and evaluate (

1/2).

(b) Show that (

1/2) (2n) = 22n−1 (n) (n+1/2).

(m,n) = (n,m). [6+6+4]

2. (a) Define analyticity of a complex function at a point P and in a domain D.

Prove that the real and imaginary parts of an analytic function satisfy Cauchy

Riemann Equations.

(b) Show that the function defined by

f(z) = x3(1+i)−y3(1−i)

2+y2 at z 6= 0 and f(0) = 0

is continuous and satisfies C-R equations at the origin but f

0(0) does not exist.

[8+8]

3. (a) Evaluate

(

−

2z−2) dz

(

z2+1)2z where c is | z − i | = 1/2 using Cauchy’s integral for-

mula.

(b) Evaluate

(

z2 + 3z + 2)dz where C is the arc of the cycloid x = a( + sin ),

= a (1 − cos ) between the points (0,0) to ( a, 2a). [8+8]

4. (a) Show that

(

a2+sin2 ) =

1+a2 , ( a > 0) using residue theorem.

(b) Evaluate

(

x4+1) using Residue theorem. [8+8]

5. (a) Under the transformation w=1/z, find the image of the circle

|z-2i|=2.

(b) Under the transformation

w = z−i

−iz , find the image of the circle |z|=1 in the

w-plane. [8+8]

6. A covariant tensor has components x+y, xy, 2z-

y2 in rectangular coordinates. Find

its covariant components in cylindrical coordinates. [16]

7. (a) If A and B are events with P(A) = 1/3, P(B) = 1/4, and P(A U B) = 1/2,

find

i. P(A/B)

ii. P(A

\Bc ).

(b) Three students A,B,C are in a running race. A and B have the same probability

of wining and each is twice as likely to win as C. Find the probability that B

or C wins.

1 of 2

Code No: T2101/R05

Set No. 1

examination. Find the probability that the boys and girls are alternate if

there are.

i. 5 boys and 4 girls

ii. 4 boys and 4 girls. [6+5+5]

8. (a) Suppose a continuous random variable X has the probability density

f(x)=k(1

− x2) for0 < x < 1, and f(x) = 0 otherwise. Find

i. k

ii. mean

iii. variance.

(b) The scores of two golfers for 10 rounds each are

A: 58 59 60 54 65 66 52 75 69 52

B 84 56 92 65 86 78 44 54 78 68

Which may be regarded as the more consistant player. [8+8]

? ? ? ? ?

2 of 2

Code No: T2101/R05

Set No. 2

II B.Tech II Semester Supplementary Examinations, December 2009

MATHEMATICS FOR AEROSPACE ENGINEERS

(Aeronautical Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Prove that

J0 (x) = 1 − x2

2 + x4

2.42 − x6

2 .42.62+............

(b)

−

nPn(x)dx = 2n+1.(n!)2

n+1)! . [8+8]

2. (a) Show that

(z) = xy2(x+iy)

2+y2 , z 6= 0

= 0

if z = 0

is not analytic at z =0 although C –R equations are satisfied at the origin.

(b) If ( x + iy )

1/3= a + ib , then prove that 4 ( a2–b2) = x

+ y

. [8+8]

3. (a) Expand log(1+z) as Taylor series about z = 0 and determine the region of

convergence for the resulting series.

(b) State and prove Laurent theorem. [8+8]

4. (a) Evaluate

−3 sin )2 using residue theorem.

(b) Evaluate

sin mx dx

4+16 using residue theorem. [8+8]

5. (a) Find the image of 1

< |z| <2 under the transformation w= 2iz+1.

(b) Find the bilinear transformation which maps the points (–1, i, 1+i ) onto the

points (0, 2i, 1-i). [8+8]

6. (a) A covariant tensor has components 2xz,

x2y, yz in cartesian coordinate system.

Find its components in cylindrical coordinates.

(b) Show that the any inner product of the tensors

and Bqs

is a tensor of rank

three. [8+8]

7. (a) Two cards are selected at random from 10 cards numbered 1 to 10. Find the

probability that the sum is even if

i. the two cards are drawn together

ii. the two cards are drawn one after the other with replacement.

(b) State and prove Baye’s theorem.

, 3

, 2

The

probabilities that bonus scheme will be introduced if they become M.D’s are

.02, .03 and .04. Find the probabilities A,B,C to be become M.D’s if bonus

scheme introduced. [5+5+6]

1 of 2

Code No: T2101/R05

Set No. 2

8. (a) Using recurrence formula find the probabilities when x=0, 1, 2, 3, 4 and 5 If

the mean of Poisson distribution is 3.

(b) If the masses of 300 students are normally distributed with mean 68kgs and

standard deviation 3kgs how many students have masses.

i. Greater then 72 kg

ii. Less than or equal to 64 kg

iii. Between 65 and 71 kg inclusive. [8+8]

? ? ? ? ?

2 of 2

Code No: T2101/R05

Set No. 3

II B.Tech II Semester Supplementary Examinations, December 2009

MATHEMATICS FOR AEROSPACE ENGINEERS

(Aeronautical Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Show that

me−axndx = 1

(

m+1

)

((

m + 1)/n) where n and m are positive

constants.

(b) Prove that

−y1/mdy = m (m).

(

x − a)m(b − x)ndx = (b − a)m+n+1 (m + 1, n + 1). [5+5+6]

2. (a) Find an analytic function f(z) = u(r,

)+ i v(r, ) such that

u(r,

) = r2cos2 – r cos + 2.

(b) Determine ‘p’ such that the function f(z) =

loge(x2+y2) + i tan−1 px

an analytic function. [8+8]

3. (a) Evaluate

(

z 2 − z−1) dz

(z−i)2 with C:

− 1/2

= 1 Using Cauchy’s integral theo-

rem.

(b)

(

z 2 + 4) dz

2(z+2)2 with C: | z + 2 | = 1 using Cauchy’s integral formula. [8+8]

4. (a) Find the poles and residues at each pole of the function

(2z+1)

(

z2−z−2) .

(b) Evaluate

z−4)dz

(z−1)(z−2) by residue theorem where C |z| = 3. [8+8]

5. (a) Find the image of the circle

|z|=2, under the transformation w=z+3+2i.

(b) The points (0, –i, –1) are mapped into the points (i, 1, 0). Find the image of

the line y = mx under this transformation. [8+8]

6. (a) Determine the fundamental and reciprocal tensor in (

ds)2 = 3(x1)2 + 3(x3)2

+ 4

x1x2 + 8x1x3 + 8x2x3.

(b) If

ds2 = 5 (dx1)2 + (dx2)2 + 4 (dx3)2 − 6 (dx1) (dx2) + 4 (dx2) (dx3) find the

values of

gij and gij . [8+8]

7. (a) The probabilities that students A,B,C,D solve a problem are 1/3, 2/5, 1/5

and 1/4 respectively. If all of them try to solve the problem, what is the

probability that the problem is solved.

(b) In a bolt factory machines A,B,C manufacture 20%

, 30% and 50% of the total

of their output and 6%

, 3% and 2% are defective. A bolt is drawn at random

and found to be defective. Find the probabilities that it is manufactured from

1 of 2

Code No: T2101/R05

Set No. 3

i. Machine A

ii. Machine B

iii. Machine C. [8+8]

8. (a) Suppose 2% of the people on the average are left handed. Find

i. the probability of finding 3 or more left handed

ii. the probability of finding

1 left handed.

(b) The mean and standard deviation of a normal variate are 8 and 4 respectively

find

i. P(5

x 10)

ii. P(x

5). [8+8]

? ? ? ? ?

2 of 2

Code No: T2101/R05

Set No. 4

II B.Tech II Semester Supplementary Examinations, December 2009

MATHEMATICS FOR AEROSPACE ENGINEERS

(Aeronautical Engineering)

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

? ? ? ? ?

1. (a) Prove that

(m, n) = (n−1)

(m + 1, n − 1).

(b) Evaluate

p(1+x4)

function dx px (1+x2) . [5+5+6]

2. (a) Find the analytic function whose imaginary part is

f(x,y) = x

3y – xy3 + xy +x +y where z = x+iy.

(b) Prove that

2 + @2

2 |Real f(z)|2 = 2|f0(z)|2 where w =f(z) is analytic.

[8+8]

3. (a) Evaluate using Cauchy’s integral formula

(

z+1)dz

2+2z+4 where C :| z + 1 + i | = 2.

(b) Evaluate

−

dz fromz

= 0 to 4 + 2i along the curve C given by

i. z=t

2+it

ii. Along the line z=0 to z=2 and then from z=2 to 4+2i. [8+8]

4. (a) Use method of contour integration to prove that

a2−2acos = 2

−a2 ,

< a<1.

(b) Evaluate

(

x2+9)(x2+4)2 using residue theorem. [8+8]

5. (a) Find and plot the image of triangular region with vertices (0,0), (0,1), (1,0)

under the transformation W= (1-i) z+3.

(b) Determine the image of the region under the transformation

w = 1

0<y<2.

x 3, - y in the z-plane

under the transformation

w = ez. [6+5+5]

6. (a) A covariant tensor has components 2xz,

x2y, yz in cartesian coordinate system.

Find its components in cylindrical coordinates.

(b) Show that the any inner product of the tensors

and Bqs

is a tensor of rank

three. [8+8]

1 of 2

Code No: T2101/R05

Set No. 4

7. (a) The probabilities of passing in subject A, B, C, D are 3/4, 2/3, 4/5 and 1/2

respectively. To qualify in the examination a student should pass in A and

two subjects among the three what is the probability of qualifying in that

examination.

(b) There are two boxes. In box -I, 11 cards are there numbered 1 to 11 and in

box-II, 5 cards numbered 1 to 5. A box is chosen and a card is drawn. If the

card shows an even number then another card is drawn from the same box. If

card shows an odd number another card is drawn from the other box. Find

the probability that

i. Both are even

ii. Both are odd. [8+8]

8. (a) If f(x) = K

e−|x| is a probability density function in −1< x <1, find

i. The value of k,

ii. the variance

iii. The probability between 0 and 4.

(b) Derive the mean and variance of the Binomial distribution. [8+8]

? ? ? ? ?

2 of 2

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