electrical engineering solved question papers

electrical engineering solved question papers
Solved Question Papers for Electrical Available Online
Solved Question Papers Of electrical engineering
Directions: The following items consist of two statements, one labelled the ‘Assertion A’ and the other labelled the ‘Reason R’. You are to examine these two statements carefully and decide if the Assertion A and the Reason R is individually true and if so, whether the Reason is a correct explanation of the Assertion. Select your answer to these items using the codes given below and mark your answer sheet accordingly.
Codes:
(a) Both A and R is true and R is the correct explanation of A
(b) Both A and R is true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true



1. Assertion (A): Mho relay is widely preferred for the protection of long transmission lines.
Reason (R): Mho relay is stable under power swing conditions.

Ans:-A


2. If I(s) is found to be
1 / s(s+2)(s+5)
then the final value of I (i.e. I at t = ? will be
(a) 10
(b) 1.0
(c) 0.667
(d) 0.1

Ans:-D



3. In a series RLC circuit, the voltage across the inductance as a function of frequency will be maximum
(a) just before resonant frequency
(b) at resonant frequency
(c) just after resonant frequency
(d) both just before and just after resonant frequency

Ans:-C
4. In a balanced delta connected resistive load when one resistor is open-circuited, then the power drawn by the load
(a) is reduced by 1/3
(b) is increased by 1/3
(c) remains same
(d) is reduced by 1/2

Ans:-A


5. Two perfectly coupled coils each of one Henry self-Inductance are connected In parallel so as to aid each other. The overall Inductance is
(a) 2H
(b) 1H
(c) l/2H
(d) zero

Ans:-C



6. Consider the components of E and H listed below:
1.Ex
2.Ey
3.Ex
4.Hy
5.Hz
For a plane wave travelling in x-direction and linearly polarizes in y-direction
(a) 1, 2 and 5 exist
(b) 1, 3 and 4 exist;
(c) 3 and 4 exist
(d) 2 and 5 exist

Ans:-A


7. For a standard feedback control loop, the sensitivity of the closed-loop transfer function T to forward path gain G and feedback path gain H are

STG STH
(a) 1/(1+GH) —1/(1 +GH)
(b) —GH(1+GH) —H/(1 + GH)
(c) G/(1 +GH) 1/(1 + GH)
(d) 1/(1+GH) -GH/(1 + GH)

Ans:-D







8. Consider the following features:
1. Its pole is located to the left of its zero.
2. It decreases the margin of stability of the system.
3. It speeds up the system transient response. Those associated with a lead compensator would include
(a) l, 2 and 3
(b) 1 and 2
(c) 2 and 3
(d) l and 3

Ans:-D

9. A servomotor is usually designed to have
(a) high rotor inertia and high bearing friction
(b) high rotor inertia and low bearing friction
(c) low rotor inertia and high bearing friction
(d) low rotor inertia and low bearing friction

Ans:-D

10. Match List I with List II and select the correct answer using the codes given below the lists:
List I
(Measuring Bridge)
A. Maxwell bridge
B. Anderson bridge
C. Heaviside Campbell bridge

List II
(Unknown self- inductance is compared with)
1. Known value of self-inductance
2. Known value of capacitor
3. Known value of mutual inductance
Codes:
A B C
(a) 1 2 3
(b) 1 3 2
(c) 3 1 2
(d) 2 1 3

Ans:-A





11. Which of the following compensations are provided in the induction type energy meter for correct measurement of energy?
1. Friction compensation
2 Power factor compensation
3. Frequency compensation
4. Overload Compensation
Select the correct answer from the codes given below:
Codes
(a) 1, 2 and 3
(b) l, 2 and 4
(c) l, 3 and 4
(d) 2, 3 and 4

Ans:-B


12. To measure the angular position ? of a shaft which is free to rotate continuously and if the measurement is to be carried out with high precision, the transducer to be selected would be
(a) potentiometer
(b) synchro
(c) resolver
(d) tachometer

Ans:-B


13.. A piezoelectric transducer has the following parameter values:
Crystal capacitance = 10-9 F
Cable capacitance = 2 x 1010F
Charge sensitivity = 4 x 10-6 coulombs/cm
if the oscilloscope used for read-out has input resistance of 1 M? In parallel with
C = 4 x 10-10F, then the voltage sensitivity constant will be
(a) 2500 volts/cm
(b) 3334 volts/cm
(c) 4000 volts/cm
(d) 4500 volts/cm

Ans:-A







14. In a certain telemetry system, the measured values are converted to digital form. The digital values can then be transmitted via FSK (binary or quaternary) or BPSK or QPSK systems. Out of these, the best noise immunity can be obtained with.
(a) binary FSK
(b) quaternary FSK
(c) BPSK
(d) QPSK

Ans:-B


15. What is the correct increasing order of the following frequencies connected with the junction transistor operation?
1. fT
2. f?
3. f?
Select the correct answer from the codes given below:
Codes:
(a) 1,2,3
(b) 2,3,1
(c) 2,1,3
(d) 3,1,2

Ans:-C


16. The h parameter equivalent circuit is the most common representation of the junction transistor because
(a) it is usable over the entire frequency band of interest to the transistor
(b) the parameters values correspond to input impedance, output admittance and current gain for the most common applications of the transistor
(c) it represents the admittance parameters of the transistors
(d) it is most useful in the ON and OFF states of the transistor

Ans:-A




17. A power amplifier uses transistor of maximum power dissipation rating of 10 watts. Match the operating classes of List I with possible output power ratings of List II and select the correct answer using the codes given below the lists:
List I
(Operation)
A. Single-ended class A
B. Push-pull class A
C. Single-ended class B
D. Push-pull class B
List II
(Ideal Power Output)
1. l0W
B. 20W
C. 30W
4. 37W
Codes:
A B C D
(a) 1 1 4 4
(b) 2 2 3 3
(c) 3 3 4 4
(d) 1 2 3 4

Ans:-C




18. A carrier voltage is simultaneously amplitude modulated by two sine waves causing modulation in dices of 0.4 and 0.3. The overall rms value of modulation index Is
(a) 0.10
(b) 0.35
(c) 0.50
(d) 0.70

Ans:-B


19. An AM transmitter radiates 4 kW with an unmodulated carrier wave and 5 kW when it is amplitude modulated. If the carrier were frequency modulated, then the radiated power will be
(a) 4kW
(b) 5kW
(c) 4.5kW
(d) 8kW

Ans:-A



20. Which one of the following pairs is not correctly matched?
(a) Amplitude demodulation circuit: Diode detector
(b) Frequency demodulation circuit: Ratio detector
(c) Phase demodulation circuit: Coherent detector
(d) Pulse demodulation circuit: TDM

Ans:-C

21. How many steps are there in the output of a 10- bit D/A converter?
(a) 1023
(b) 1024
(c) 10
(d) 100

Ans:-A


22. Match List I with List II and select the correct answer using the codes given below the lists:
List I
(.Types of AID converters)
A. Dual Slope
B. Counter-Ramp
C. Successive Approximation
D. Simultaneous
List II
(Properties of AID converters)
1. Fixed conversion time; depends on the no.
of bits
2. High speed operation
3. Hum rejection
4. Conversion time dependent on signal amplitude
5. Large conversion time
Codes:
A B C D
(a) 3 2 5 4
(b) 2 3 4 1
(c) 3 4 1 2
(d) 4 1 2 5

Ans:-A





23. What Is the 2‘s complement of the word 0011 0101 1001 1100?
(a) 1100 1010 0110 0100
(b) 1100 1010 0110 0011
(c) 1100 1010 0110 0101
(d) 0011 0101 1001 1101

Ans:-A


24. There is a sequential circuit which has “N” number of states. If states S1 and S1 can be distinguished by an input sequence of length n, then
(a) n ? N
(b) n ? N—1
(c) n ? N
(d) n ? N—1

Ans:-D


25. The fastest mode of data transfer from CPU to memory in a microprocessor is
(a) memory mapped I/O
(b) 1/0 mapped I/O
(c) interrupt driven I/O
(d) DMA

Ans:-D


26. In the execution of following instructions
MOV AH, MEM
SHR AH, I
SHR AH, I
MOV MEM, AH
which one of the following would hold true?
(a) MEM gets divided by 4
(b) 25 gets added to MEM
(c) 25 gets subtracted from MEM
(d) MEM gets multiplied by 4

Ans:-C






27. Flat top sampling of base band signals leads to
(a) aliasing
(b) aperture effect
(c) under-sampling
(d) impossible reconstruction

Ans:-B


28. The figure-of-merit of an earth station in satellite communication system is specified in terms of
(a) noise temperature
(b) antenna gain
(c) gain-to-noise temperature ratio
(d) sensitivity of the receiver

Ans:-C


29. Consider the following statements: Odd line 2: I. interlacing in television helps in
1. reducing flicker
2. simplifying vertical motion circuitry
3. horizontal synchronisation
4. separation of synchronizing pulse
Of these statements:
(a) 1 and 2 are correct
(b) 2 and 3 are correct
(c) 1 and 4 are correct
(d) 2 and 4 are correct

Ans:-C


30. Serrations are used in the composite video waveform of a television system to
(a) facilitate interlacing
(b) aid generation of vertical sync pulse
(c) aid vertical synchronisation
(d) aid horizontal synchronisation

Ans:-A