As you are looking for the solved question paper of IES Electrical Engineering Exam, so here I am sharing the same with you

1) The unit of magnetic flux density is

a) weber/sec
b) bohr
c) tesla
d)gauss

Ans :c

2) A Pelton wheel turbine having a rated speed. Of 300 rpm is connected to an alternator to produce power at 50 Hz. The number of poles required in the alternator is

a)20
b)30
c)9
d)4

Ans :a

3) The electric field in the vicinity of two oppositely charged parallel conductors is

a) in parallel circular paths between the two conductors, with the centre of the circles located at the mid-point of a line joining the two centres of the two conductors
b) not uniform and its direction changes from point to point
c) in parallel lines between the two imaginary parallel planes passing through the centres of the two conductors
d) radial uniformly

Ans :a

4) Consider the following statements with regard to synchronous machines :

1. When a synchronous motor is over – excited, its back emf is greater than the supply voltage
2. When a synchronous motor is over – excited, its power factor is leading.
3. Synchronous motor is used as a capacitor where load is so large that construction of a static capacitor is impractical.

Correct statements are

a) 1, 2 and 3
b) 2 and 3 only
c) 1 and 3 only
d) 1 and 2 only

Ans :a

5) Two charges are placed at a distance apart. Now, if a glass slab is inserted between them, then the force between the charges will

a) not change
b) decrease
c) increase
d) reduce to zero

Ans :b

6) A large synchronous generator is feeding power into an infinite bus at slightly lagging power factor. If a total loss of field occurs and the system can supply sufficient reactive power without a large terminal voltage drop, the unit will

a) Run as a synchronous motor and it should be tripped after a time delay
b) Run as an induction generator and it should be tripped after a time delay
c) Get short – circuited and it should be tripped instantaneously
d) Continue to run as a synchronous generator and no tripping is necessary

Ans :b

7) What is the effect of lag compensator on the system bandwidth and the signal-to-noise ratio?

a) Bandwidth is reduced and signal-to-noise ratio is improved
b) Bandwidth is reduced and signal-to-noise ratio is deteriorated
c) Bandwidth is increased and signal-to-noise ratio is deteriorated
d) Bandwidth is increased and signal-to-noise ratio is improved

Ans :a

8) DPCM is particularly suited for

a) Seismic signals transmission
b) Speech signals transmission
c) Radio signals transmission
d) Radar signals transmission

Ans :b

9) The presence of one of the following materials, in iron or steel for use as a magnetic material, tends to reduce the hysteresis loss

a) Silicon
b) Phosphorus
c) Sulphur
d)Carbon

Ans :a

10) Frequency frogging is used in carrier system to

a) Reduce bandwidth
b) Reduce cross talk
c) Reduce distortion
d) Conserve frequencies

Ans :b

11) The equation of continuity defines the relation between

a) current density and charge density
b) electric field and charge density
c) flux density and charge density
d) electric field and magnetic field

Ans :a

12) A comparison of FDM and TDM systems shows that

a) FDM requires more multiplexing, while TDM requires band – pass filter
b) FDM requires channel synchronization, while TDM has greater noise immunity
c) FDM has greater noise immunity and requires lower bandwidth than TDM
d) FDM requires lower bandwidth, but TDM has greater noise immunity

Ans :b

13) As a result of reflections from a plane conducting wall, electromagnetic waves acquire an apparent velocity greater than the velocity of light in space. This is called

a) phase velocity
b) group velocity
c) normal velocity
d) velocity propagation

Ans :a

14) In time division multiplexing, cross talk may be avoided by

a) Proper quantization
b) Increasing the amplitude of signal
c) Proper selection of time of sampling
d) Proper base band filtering

Ans :d

15) The depth of penetration of a wave in a lossy dielectric increases with increasing

a) permittivity
b) wavelength
c) permeability
d) conductivity

Ans :b

16) The following is a unipolar device :

a) MOSFET
b) GTO
c) IGBT
d) BJT

Ans :a

17) It is possible to destroy the super conductivity of a material by applying

a) a pressure below that of the atmosphere
b) a strong electric field
c) a temperature much below the transition temperature
d) a strong magnetic field

Ans :d

18) A thyrister has a PIV of 650 V. The voltage safety factor is 2. Then the voltage upto which the device can be operated is given by

a) 230 V
b) 330 V
c) 270 V
d) 130 V

Ans :a

19) High-frequency transformer cores are generally made from

a) Cobalt
b) ferrites
c) Mone-metal
d) Mu-metal

Ans :b

20) When a thyristor is in the forward blocking state, then

a) Anode and gate junctions are forward biased but cathode is reverse biased
b) Anode junction is forward biased but other two are reverse biased
c) Anode and cathode junctions are forward biased but gate junction is reverse biased
d) All 3 junctions are reverse biased

Ans :c

21) A coil having 250 turns is connected to a 50 V DC source. If the coil resistance is 10 Ω, the m.m.f. developed in AT would be

a)1250
b)2500
c)455
d)350

Ans :a

22) An SCR triggered by a current pulse applied to the gate – cathode can be turned off

a) By reversing the polarity of the anode and cathode voltage
b) By applying another pulse of opposite polarity to the gate – cathode
c) By applying a pulse to the anode
d) By applying a pulse to the cathode

Ans :a

23) A single-phase energy meter having meter constant of 200 rev/kWh is operating on 230V, 50 Hz supply with a load of 10 A, and at unity power factor for three hours continuously. The number of revolutions shown by the meter during this period is

a)1380
b)138
c)13800
d)13

Ans :a

24) In forward – bias portion of the thyristor’s i – v characteristic, the number of stable operating regions is

a)two
b)three
c)one
d)none

Ans :a

25) The maximum power will be transferred from a voltage source to a load when

a) both source and load impedances must be zero
b) the source impedance is twice that of the load impedance
c) the source impedance is equal to that of the load impedance
d) the source impedance is half that of the load impedance

Ans :c

26) A three – phase semi – converter feeds the armature of a separately excited dc motor supplying a non – zero load torque. For steady state operation the motor current is found to assume zero value at certain instances of time. At such instances the armature voltage.

a) Becomes zero
b) Assumes an arbitrary value
c) Is equal to the instantaneous value of motor back emf
d) Is equal to the instantaneous value of ac voltage

Ans :c

27) In a linear network, a 1 Ω resistor consumes a power of 4 W when voltage source of 4 V is applied to the entire circuit, and 16 W when the voltage source is replaced by an 8 V source. The power consumed by the 1Ω resistor when 12 V is applied will be

a)36 W
b)0W
c)12 W
d)24W

Ans :a

28) A single – phase two pulse converter feeds an R – L load with insufficient smoothing but the conduction is continuous. If the resistance of the load circuit is increased, then

a) There is possibility of discontinuous conduction due to an increase in the ripple content.
b) The ripple content of the load current will increase
c) The ripple content of the load current will decrease
d) The ripple content of the load current will remain the same

Ans :a

29) Consider the following statements: Any element connected in

1. series with a voltage source is redundant
2. parallel with a voltage source is redundant
3. series with a current source is redundant
4. parallel with a current source is redundant

The correct statements are

a) 1 and 2
b) 3 and 4
c) 2 and 3
d) 1 and 3

Ans :c

30) A voltage source inverter is normally employed when

a) Both source inductance and load inductance are large
b) Both source inductance and load inductance are small
c) Source inductance is small and load inductance is large
d) Source inductance is large and load inductance is small

Ans : c

31) The lowest and the highest critical frequencies of R-C driving-point impedance are respectively

a) pole and a zero
b) a zero and a zero
c) a pole and a pole
d) a zero and a pole

Ans :a

IES Electrical Paper

32) A current source inverter is obtained by inserting a large

a) Capacitance in series with dc supply
b) Inductance in parallel with dc supply
c) Capacitance in parallel with dc supply
d) Inductance in series with dc supply

Ans :d

33) For an R-L-C series circuit in resonance, the following statement in not correct

a) The voltage drops across the capacitance and inductance are unequal in magnitude
b) The voltage drops across the resistance is maximum
c) The voltage phasors across the capacitance and inductance are unequal
d) The current is maximum

Ans :a

34) Among the following pairs, the one not correctly matched is

a) DIAC – Firing voltage
b) TRIAC – Breakdown voltage
c) FET – Pinch-off voltage
d) UJT – Intrinsic stand-off ratio

Ans :a

35) A coil of resistance 20 Ω and inductance 0.8 H is connected to a 200 V DC supply. The rate of change of current at t=0+ is

a) 4000 A/s
b) 250 A/s
c) 160A/s
d) 16 A/s

Ans :b

36) Digital modulating system among the following is

a) PFM
b) PWM
c) PCM
d) PPM

Ans :c

37) When a unit impulse voltage is applied to an inductor of 1 H, the energy supplied by the source is

a)1/4 J
b)1/2 J
c)1 J
d)2J

Ans :b

38) In a super – heterodyne receiver, the frequency of local oscillator is

a) Equal to that of incoming signal
b) Higher than that of incoming signal
c) Slightly less than that of incoming signal
d) Half that of incoming signal

Ans :b

39) The number of independent KVL and KCL equations for a network with n nodes and l links are respectively

a) n-1 and l-1
b) n-1 and l
c) l and n-1
d) l and n

Ans :c

40) The following events will not happen when quantizing noise is decreased in PCM :

a) Decrease in randomness due to difference in digit sent and actual signal at an instant
b) Decrease in channel noise
c) Increase in bandwidth
d) Increase in the number of standard levels

Ans : a

41) The total number of branches in a network is equal to b. The graph of the network has n number of branches. The minimum number of line currents is

a)n
b)b-n
c)b
d) b+n

Ans :b

IES Electrical Paper

42) The type of noise reduced by limiters in FM receivers is

a) Impulse noise
b) Narrow band – pass noise
c) Burst noise
d) Avalanche noise

Ans :c

43) When a steady current is passed through a ballistic galvanometer, then the deflection will be

a) None of the above
b) twice the normal value as it depends on Hibbert magnetic standard
c) zero
d)maximum

Ans :c

44) The maximum deviation allowed in a frequency modulation system is 100 kHz; the modulating signal frequency is 10 kHz. The bandwidth requirement as per Carson’s rule will be

a) 150 kHz
b) 210 kHz
c) 120 kHz
d) 220 kHz

Ans :d

45) The measurement of frequency can be carried out with

a) Schering’s bridge
b) Maxwell’s inductance-capacitance bridge
c) Wien’s bridge
d) Owen’s bridge

Ans :c

46) Bandwidth occupied by 100 MHz carrier, AM modulated by signal frequency of 10 kHz is

a) 20 kHz
b) 110 MHz
c) 120 kHz
d) 10 MHz

Ans :a

47) An angular deflection type indicating PMMC meter is provided with spring control and

a) damping by air dashpot
b) electromagnetic damping in the aluminium former and the moving coil as well
c) no damping
d) electromagnetic damping in the aluminium former only

Ans : d

48) All types of linear modulation can be detected by

a) Linear detector
b) Filtering
c) Envelop detector
d) Product demodulator

Ans :d

49) An advantage of PMMC instrument is that it

a) can be used on both AC and DC
b) has low torque-to-weight ratio
c) has high torque-to-weight ratio of moving parts
d) is free from friction error

Ans :c

50) Good voice reproduction via PCM requires 128 quantization levels. If bandwidth of voice channel is 4 kHz, then data rate is

a) 56 kbps
b) 16 kbps
c) 256 kbps
d) 156 kbps

Ans :a

IES Electrical paper:-

51) The following is not essential for the working of an indicating instrument

a) Controlling torque
b) Damping torque
c) Braking torque
d) Deflecting torque

Ans :c

52) One of the main functions of RF stage amplifier in Super Heterodyne Radio Receiver is to

a) Improve rejection of image frequency
b) Improve rejection of image frequency
c) Permit better adjacent channel rejection
d) Provide improved tracking

Ans :a

53) Systematic error of an instrument for measurement can be minimized by

a) carrying out all of the below
b) applying correction factors for change of ambient conditions
c) calibrating the measuring device against a standard device
d) selecting a proper measuring device for the particular application

Ans :a

54) In double sideband suppressed carrier modulation, the modulated wave undergoes phase reversal, whenever

a) Carrier signal crosses zero
b) Modulating signal crosses zero
c) Modulating signal’s amplitude increases
d) Modulating signal’s amplitude decreases

Ans :b

55) The following material is not used for making a piezoelectric transducer

a) Quartz
b) Chlorium sulphide
c) Barium titanate
d) Rochelle salt

Ans :b

56) Number of address lines necessary to connect 8 k memory chip is

a)13
b)10
c)19
d)14

Ans :a

57) A linear displacement digital transducer uses

a) binary code
b) hexadecimal code
c) Gray code
d) BCD code

Ans :c

58) How many initialization Command Words are essential if 8259 is used in single chip with special fully nested mode configuration ?

a)4
b)5
c)6
d)2

Ans :d

59) An electronic voltmeter gives more accurate readings in high resistance circuits as compared to a non-electronic voltmeter because of its

a) high resolution
b) high V/kohm rating
c) high k ohm/V rating
d) low meter resistance

Ans :c

60) In case of dynamic memory

a) The speed is low as compared to static memory
b) Power consumption is low
c) Contents are retained without distortion
d) Contents tend to decay over a period of time

Ans :a,b & d

61) By mistake, an ammeter is used as a voltmeter. In all probabilities, it will

a) get damaged
b) indicate no reading at all
c) give extremely low reading
d) give much higher reading

Ans :a

62) The following is not true for RS232 standard :

a) It defines standard connector configurations
b) Does not decide data transmission rate
c) It defines signal voltage levels
d) It establishes the way data is coded

Ans :b

63) The meter constant of a single-phase energy meter is 500 rev/kWh. It is found that with a load of 5 kW, it makes 40 revolutions in 50 sec. The percentage error is

a)15.25 %
b)5.25%
c)2%
d)6%

Ans :a

64) An 8085 microprocessor based system uses a 4K x 8 – bit RAM whose starting address is AA00H. The address of the last byte in this RAM is

a) BA00H
b) B9FFH
c) 1000H
d) 0FFFH

Ans :b

65) The pressure in a tank varies from 20 psi to 100 psi. The pressure in the tank is desired to be kept at 50 psi. The full-scale error when the pressure inside the tank is 30 psi will be

a)25%
b)30%
c)50%
d)5%

Ans :a

66) The instruction PCHL in 8085 is used for

a) Load PC with the contents of memory location pointed by HL pair
b) Load Hl with contents of PC
c) Load HL with contents of memory location pointed by PC
d) Load PC with contents of HL

Ans :d

67) Which of the following are the objectives of a data acquisition system?

1. It must acquire necessary data at correct speed and time.
2. It must collect and store data.
3. There should be provision for real-time data display.
4. There should be provision for stored data display on request.

a) 2, 3 and 4 only
b) 1, 2, 3 and 4
c) 1, 3 and 4 only
d) 1,2 and 3 only

Ans :b

68) When referring to instruction words, amnemonic is

a) Shorthand for machine language
b) A short abbreviation for the data word stored at the operand address
c) A short abbreviation for the operation to be performed
d) A short abbreviation for the operand address

Ans :c

69) Analog data acquisition systems are used when

a) narrow bandwidth and high accuracy are required
b) wide bandwidth and high accuracy are required
c) narrow bandwidth and low accuracy are required/sufficient
d) wide bandwidth and low accuracy are required/sufficient

Ans : d

70) For a memory system, the cycle time is

a) Sub – multiple of the access time
b) Shorter than the access time
c) Larger than the access time
d) Same as the access time