karthiklara

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Q. No. 1 – 20 Carry One Mark Each
1. The pressure coil of a dynamometer type wattmeter is
(A) highly inductive (B) highly resistive
(C) purely resistive (D) purely inductive
2. The measurement system shown in the figure uses three sub-systems in cascade
whose gains are specified as 1 2
3
1
G , G and
G
. The relative small errors associated
with each respective subsystem 1 G , G2 and G3 are e1, e2 and e3 . The error
associated with the output is:
(A) 1 2
3
1 e + e +
e
(B) 1 2
3
e .e
e
(C) 1 2 3 e + e − e (D) 1 2 3 e + e + e
3. The following circuit has a source voltage Vs as shown in the graph. The current
through the circuit is also shown.
The element connected between a and b could be
(A) (B)
(C) (D)
Input 1 G 2 G
3
1
G
Output
Vs
+
−
a b
R 10k
15
10
5
0
5
10
15
−
−
−
0 100 200 300 400
Vs (volts)
Time (ms)
1.5
1
0.5
0
0.5
1
1.5
−
−
−
0 100 200 300 400
Current (mA)
Time (ms)
a b
a b
a b
a b
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4. The two inputs of a CRO are fed with two stationary periodic signals. In the X-Y
mode, the screen shows a figure which changes from ellipse to circle and back to
ellipse with its major axis changing orientation slowly and repeatedly. The
following inference can be made from this.
(A) The signals are not sinusoidal
(B) The amplitudes of the signals are very close but not equal
(C) The signals are sinusoidal with their frequencies very close but not equal
(D) There is a constant but small phase difference between the signals
5. The increasing order of speed of data access for the following devices is
(i) Cache Memory
(ii) CDROM
(iii) Dynamic RAM
(iv) Processor Registers
(v) Magnetic Tape
(A) (v), (ii), (iii) , (iv), (i) (B) (v), (ii), (iii) , (i), (iv)
(C) (ii), (i) , (iii), (iv), (v) (D) (v), (ii), (i), (iii), (iv)
6. A field excitation of 20 A in a certain alternator results in an armature current of
400A in short circuit and a terminal voltage of 2000V on open circuit. The
magnitude of the internal voltage drop within the machine at a load current of
200A is
(A) 1V (B) 10V (C) 100V (D) 1000V
7. The current through the 2 kW resistance in the circuit shown is
(A) 0mA (B) 1mA (C) 2mA (D) 6mA
8. Out of the following plant categories
(i) Nuclear (ii) Run-of-river (iii) Pump Storage (iv) Diesel
The base load power plants are
(A) (i) and (ii) (B) (ii) and (iii) (C) (i), (ii) and (iv) (D) (i), (iii) & (iv)
9. For a fixed value of complex power flow in a transmission line having a sending
end voltage V, the real power loss will be proportional to
(A) V (B) V2 (C) 1/V2 (D) 1/V
A B
6V
1kW 1kW
1kW 1kW
2kW
C
D
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10. How many 200W/220V incandescent lamps connected in series would consume
the same total power as a single 100W/220V incandescent lamp?
(A) not possible (B) 4 (C) 3 (D) 2
11. A Linear Time Invariant system with an impulse response h(t) produces output
y(t) when input x(t) is applied. When the input x (t − t) is applied to a system
with impulse response h(t − t) , the output will be
(A) y (t) (B) y (2(t − t)) (C) y (t − t) (D) y (t − 2t)
12. The nature of feedback in the opamp circuit shown is
(A) Current - Current feedback
(B) Voltage - Voltage feedback
(C) Current - Voltage feedback
(D) Voltage - Current feedback
13. The complete set of only those Logic Gates designated as Universal Gates is
(A) NOT, OR and AND Gates (B) XNOR, NOR and NAND Gate
(C) NOR and NAND Gates (D) XOR, NOR and NAND Gates
14. The single phase, 50Hz, iron core transformer in the circuit has both the vertical
arms of cross sectional area 20cm2 and both the horizontal arms of cross
sectional area 10cm2. If the two windings shown were wound instead on opposite
horizontal arms, the mutual inductance will
(A) double
(B) remain same
(C) be halved
(D) become one quarter
15. A 3-phase squirrel cage induction motor supplied from a balanced 3-phase source
drives a mechanical load. The torque-speed characteristics of the motor (solid
curve) and of the load (dotted curve) are shown. Of the two equilibrium points A
and B, which of the following options correctly describes the stability of A and B?
(A) A is stable B is unstable
(B) A is unstable B is stable
(C) Both are stable
(D) Both are unstable

1kW
Vin
2kW
Vout
+6V
−6V
−
+
sync
N
0 N
A
B
1.0
Torque
•
•
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16. An SCR is considered to be a semi-controlled device because
(A) it can be turned OFF but not ON with a gate pulse
(B) it conducts only during one half-cycle of an alternating current wave
(C) it can be turned ON but not OFF with a gate pulse
(D) it can be turned ON only during one half-cycle of an alternating voltage wave
17. The polar plot of an open loop stable system is shown below. The closed loop
system is
(A) Always stable
(B) Marginally stable
(C) Unstable with one pole on the RH s-plane
(D) Unstable with two poles on the RH s-plane
18. The first two rows of Routh's tabulation of a third order equation are as follows.
3
2
s 2 2
s 4 4
. This means there are
(A) two roots at s = ±j and one root in right half s-plane
(B) two roots at s = ±j2 and one root in left half s-plane
(C) two roots at s = ±j2 and one root in right half s-plane
(D) two roots at s = ±j and one root in left half s-plane
19. The asymptotic approximation of the log-magnitude vs frequency plot of a
system containing only real poles and zeros is shown. Its transfer function is
(A)
( )
( ) ( )
10 s 5
s s 2 s 25
+
+ +
(B)
( )
2 ( ) ( )
1000 s 5
s s 2 s 25
+
+ +
(C)
( )
( ) ( )
100 s 5
s s 2 s 25
+
+ +
(D)
( )
2 ( ) ( )
80 s 5
s s 2 s 25
+
+ +
0.1 2 5 2.5
80dB
−40dB / dec
−60dB / dec
wrad / s
Imaginary
Real
w = ¥
w = 0
−1.42
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20. The trace and determinant of a 2×2 matrix are known to be -2 and -35
respectively. Its eigen values are
(A) -30 and -5 (B) -37 and -1 (C) -7 and 5 (D) 17.5 and -2
Q. No. 21 – 56 Carry Two Marks Each
21. The following circuit has R = 10kW, C = 10μF R. The input voltage is a sinusoid at
50Hz with an rms value of 10V. Under ideal conditions, the current is from the
source is
(A) 0 10pmA leading by 90
(B) 0 20pmA leading by 90
(C) 0 10mA leading by 90
(D) 0 10pmA lagging by 90
22. In the figure shown, all elements used are ideal. For time t<0, S1 remained
closed and S2 open. At t=0, S1 is opened and S2 is closed. If the voltage Vc2
across the capacitor C2 at t=0 is zero, the voltage across the capacitor
combination at t=0+ will be
(A) 1V (B) 2 V (C) 1.5 V (D) 3 V
23. Transformer and emitter follower can both be used for impedance matching at
the output of an audio amplifier. The basic relationship between the input power
Pin and output power Pout in both the cases is
(A) Pin = Pout for both transformer and emitter follower
(B) Pin > Pout for both transformer and emitter follower
(C) Pin < Pout for transformer and Pin = Pout for emitter follower
(D) Pin = Pout for transformer and Pin < Pout for emitter follower

C
10μF
R
10kW
OPAMP
+
−
10k
R
W
is
Vs=10V rms, 50Hz
S1 S2
3V
C1 1F C2 2F
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24. The equivalent capacitance of the input loop of the circuit shown is
(A) 2μF (B) 100μF (C) 200 μF (D) 4μF
25. In an 8085 microprocessor, the contents of the Accumulator, after the following
instructions are executed will become
XRA A
MVIB F0H
SUB B
(A) 01 H (B) 0F H (C) F0 H (D) 10 H
26. For the Y-bus matrix of a 4-bus system given in per unit, the buses having shunt
elements are BUS
5 2 2.5 0
2 10 2.5 4
Y j
2.5 2.5 9 4
0 4 4 8
−
= −
−

−
(A) 3 and 4 (B) 2 and 3 (C) 1 and 2 (D) 1,2 and 4
27. The unit-step response of a unity feedback system with open loop transfer
function G(s) = K/ ((s + l) (s + 2)) is shown in the figure. The value of K is
(A) 0.5 (B) 2 (C) 4 (D) 6
28. The open loop transfer function of a unity feedback system is given by
( ) ( 0.1s ) G s = e− / s . The gain margin of this system is
(A) 11.95dB (B) 17.67dB (C) 21.33dB (D 23.9dB
1
0.75
0.5
0.25
0
0 1 2 3 4
times(s)
response
input
loop
1 i 1kW
1kW
1kW
100μF
100μF
49i1
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29. Match the items in List-I with the items in List-II and select the correct answer
using the codes given below the lists.
List I List II
To Use
a. improve power factor 1. shunt reactor
b. reduce the current ripples 2. shunt capacitor
c. increase the power flow in line 3. series capacitor
d. reduce the Ferranti effect 4. series reactor
(A) a ® 2 b ® 3 c ® 4 d ®1 (B) a ® 2 b ® 4 c ® 3 d ®1
(C) a ® 4 b ® 3 c ®1 d ® 2 (D) a ® 4 b ®1 c ® 3 d ® 2
30. Match the items in List-I with the items in List-II and select the correct answer
using the codes given below the lists.
List I List II
Type of transmission line Type of distance relay preferred
a. Short Line 1. Ohm Relay
b. Medium Line 2. Reactance Relay
c. Long Line 3. Mho Relay
(A) a ® 2 b ®1 c ® 3 (B) a ® 3 b ® 2 c ®1
(C) a ®1 b ® 2 c ® 3 (D) a ®1 b ® 3 c ® 2
31. Three generators are feeding a load of 100MW. The details of the generators are
Rating(MW) Efficiency (%) Regulation (p.u.)
on 100 MVA base
Generator-1 100 20 0.02
Generator-2 100 30 0.04
Generator-3 100 40 0.03
In the event of increased load power demand, which of the following will happen?
(A) All the generators will share equal power
(B) Generator-3 will share more power compared to Generator-1
(C) Generator-1 will share more power compared to Generator-2
(D) Generator-2 will share more power compared to Generator-3
32. A 500MW, 21kV,, 50Hz, 3-phase, 2-pole synchronous generator having a rated
p.f=0.9, has a moment of inertia of 27.5 x 103 kg-m2. The inertia constant (H)
will be
(A) 2.44s (B) 2.71s (C) 4.88s (D) 5.42s
33. f(x,y) is a continuous function defined over (x, y) Î 0,1 × 0,1 . Given the two
constraints, x>y2 and y>x2, the volume under f(x,y) is
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(A) ( )
2
y 1 x y
y 0 x y
f x,y dxdy
= =
= =
(B) ( )
2 2
y 1 x 1
y x x y
f x,y dxdy
= =
= =

(C) ( )
y 1 x 1
y 0 x 0
f x,y dxdy
= =
= =
(D) ( )
y x x y
y 0 x 0
f x,y dxdy
= =
= =

34. Assume for simplicity that N people, all born in April (a month of 30 days), are
collected in a room. Consider the event of at least two people in the room being
born on the same date of the month, even if in different years, e.g. 1980 and
1985. What is the smallest N so that the probability of this event exceeds 0.5?
(A) 20 (B) 7 (C) 15 (D) 16
35. A cascade of 3 Linear Time Invariant systems is causal and unstable. From this,
we conclude that
(A) Each system in the cascade is individually causal and unstable
(B) At least one system is unstable and at least one system is causal
(C) At least one system is causal and all systems are unstable
(D) The majority are unstable and the majority are causal
36. The Fourier Series coefficient, of a periodic signal x(t), expressed as
( ) j2 kt / T
k k
x t a e
¥ p
=−¥ = are given by
2 1 0 1 2 a− = 2 − j1; a− = 0.5 + j0.2; a = j2; a = 0.5 − j0.2; a = 2 + j1;and
k a = 0; for k > 2. Which of the following is true?
(A) x(t) has finite energy because only finitely many coefficients are non-zero
(B) x(t) has zero average value because it is periodic
(C) The imaginary part of x(t) is constant
(D) The real part of x(t) is even
37. The z-transform of a signal x n is given by 4z−3 + 3z−1 + 2 − 6z2 + 2z3. It is
applied to a system, with a transfer function ( ) 1 H z = 3z− − 2 . Let the output be
y(n). Which of the following is true?
(A) y(n) is non causal with finite support
(B) y(n) is causal with infinite support
(C) y(n) = 0;|n|>3
(D) ( ) ( ) ( ) ( ) z ej z e j z ej z e j
Re Y z Re Y z ; Im Y z Im Y z ; = q = − q = q = − q
= − = − p £ q < p
38. A cubic polynomial with real coefficients
(A) can possibly have no extrema and no zero crossings
(B) may have up to three extrema and up to 2 zero crossings
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(C) cannot have more than two extrema and more than three zero crossings
(D) will always have an equal number of extrema and zero crossings
39. Let x2 -117 = 0. The iterative steps for the solution using Newton-Raphson's
method is given by
(A) k 1 k
k
1 117
x x
2 x +
   

= +

 
(B) k 1 k
k
117
x x
x + = −
(C) k
k 1 k
x
x x
117 + = − (D) k 1 k k
k
1 117
x x x
2 x +
   

= − +

 
40. ( ) ( 2 ) ( 2 )
x y F x,y = x + xy ˆa + y + xy ˆa . It's line integral over the straight line from
(x,y)= (0,2) to (x,y) = (2,0) evaluates to
(A) -8 (B) 4 (C) 8 (D) 0
41. An ideal opamp circuit and its input waveform are shown in the figures. The
output waveform of this circuit will be
(A) (B)
(C) (D)
3
2
1
0
1
2
3
−
−
−
1 t 2 t 3 t
4 t
5 t 6 t
t
V
­ V
6
0
−3
t3 t6
t ®
­ V
6
0
−3
t3 t6
t ®
­ V
6
0
−3
t2
t6
t ® t4
­ V
6
0
−3
t2 t6
t ®
t4
Vout
6V
−3V
Vin 1kW
1kW
2kW
−
+
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42. A 220V, 50Hz, single-phase induction motor has the following connection diagram
and winding orientations shown. MM'
is the axis of the main stator winding
(M1M2) and AA' is that of the auxiliary
winding (A1A2). Directions of the
winding axes indicate direction of flux
when currents in the windings are in
the directions shown. Parameters of
each winding are indicated. When
switch S is closed, the motor
(A) rotates clockwise
(B) rotates anticlockwise
(C) does not rotate
(D) rotates momentarily and comes to
a halt
43. The circuit shows an ideal diode connected to a pure inductor and is connected to
a purely sinusoidal 50Hz voltage source. Under ideal conditions the current
waveform through the inductor will look like
(A)
(B)
(C)
220V
50Hz
S A1 A2
a
a
r 1
L 10 / H
= W
= p
1 M
2 M
m
m
r 0.1
L 0.1 / H
= W
= p
A A¢
M
M¢
L = (0.1/ p)H
D+
−
s v 10sin100 t
+
= p
−

1.5
1
0.5
0
0 10 2 0 3 0 40 5 0
current
time(ms)
1.5
1
0.5
0
0 10 2 0 3 0 40 5 0
current (
)
time ms
1.5
1
0.5
0
0 10 2 0 3 0 40 5 0
current
time(ms)
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(D)
44. The Current Source Inverter shown in figure, is operated by alternately turning
on thyristor pairs (T1, T2) and (T3, T4). If the load is purely resistive, the
theoretical maximum output frequency obtainable will be
(A) 125kHz (B) 250kHz (C) 500kHz (D) 50kHz
45. In the chopper circuit shown, the main thyristor (TM) is operated at a duty ratio
of 0.8, which is much larger the commutation interval. If the maximum allowable
reapplied dv/dt on TM is 50 V/μs, what should be the theoretical minimum value
of C1? Assume current ripple through Lo to be negligible.
(A) 0.2μF (B) 0.02 μF (C) 2μF (D) 20μF
46. Match the switch arrangements on the top row to the steady-state V-I
characteristics on the lower row. The steady state operating points are shown by
large black dots
1.5
1
0.5
0
0 10 2 0 3 0 40 5 0
current
time(ms)
10A
T1
D1
D4
T 4
T 3
D3
D2
T 2
0.1μF
− +
0.1 F
− +
μ
10W
8W 0 C
0 L
0 D
1 D
1 − C +
1 L
M T
100V
+
−
A T
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(A) A − I B − II C − III D − IV (B) A − II B − IV C − I D − III
(C) A − IV B − III C − I D − II (D) A − IV B − III C − II D − I
47. For the circuit shown, find out the current flowing through the 2W resistance. Also
identify the changes to be made to double the current through the 2W resistance
(A) ( ) s 5A; Put V = 20V
(B) ( ) s 2A; Put V = 8V
(C) ( ) s 5A; Put I = 10A
(D) ( ) s 7A; Put I = 12A
48. The figure shows a three-phase delta connected load supplied from a 400V, 50
Hz, 3-phase balanced source. The pressure coil (PC) and current coil (CC) of a
wattmeter are connected to the load as shown, with the coil polarities suitably
selected to ensure a positive deflection. The wattmeter reading will be
(A) 0 (B) 1600 Watt (C) 800 Watt (D) 400 Watt
49. An average-reading digital multimeter reads 10V when fed with a triangular
wave, symmetric about the time-axis. For the same input an rms-reading meter
will read.
(A) 20 / 3 (B) 10 / 3 (C) 20 3 (D) 10 3
+ −
(A)
s i
(I)
s v
+ −
(B)
s i
(II)
s v
+ −
(C)
s i
(III)
s v
+ −
(D)
s i
(IV)
s v
± 2W
S i = 5A
S V = 4V
3-Phase
Balanced
Supply
400Volts
50Hz b c
a
2 Z
1 Z
CC
PC
( ) 1 Z = 100 + j0 W ( ) 2 Z = 100 + j0 W
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50. Figure shows the extended view of a 2 pole dc machine with 10 armature
conductors. Normal brush positions are shown by A and B, placed at the
interpolar axis. If the brushes are now shifted, in the direction of rotation, to A'
and B' as shown, the voltage waveform A B V ¢ ¢ will resemble
(A)
(B)
(C)
(D)
Common Data Questions: 51 & 52
N S
A'
+ A
+
B'
− B−
1 2 3 4 5 1' 2' 3' 4' 5'
rotation at speed w rad/ sec
A'B' V
0 0.2p 0.4p 0.6p 0.8p p
wt
A'B' V
0 0.2p 0.4p 0.6p 0.8p p
wt
A'B' V
0 0.2p 0.4p 0.6p 0.8p p
wt
A'B' V
0 0.2p 0.4p 0.6p 0.8p p
wt
A
B
C
N S1 S2
a
b
c
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The star-delta transformer shown above is excited on the star side with a
balanced, 4-wire, 3-phase, sinusoidal voltage supply of rated magnitude. The
transformer is under no load condition.
51. With both S1 and S2 open, the core flux waveform will be
(A) A sinusoid at fundamental frequency (B) Flat topped with third harmonic
(C) Peaky with third harmonic (D) None of these
52. With S2 closed and S1 open, the current waveform in the delta winding will be
(A) a sinusoid at fundamental frequency (B) flat topped with third harmonic
(C) only third harmonic (D) none of these
Common Data Questions: 53 & 54
The circuit diagram shows a two winding, lossless transformer with no leakage
flux, excited from a current source, i(t), whose waveform is also shown. The
transformer has a magnetizing inductance of 400/pmH.
53. The peak voltage across A and B, with S open is
(A) 400/pV (B) 800V (C) 4000/pV (D) 800/pV
54. If the waveform of i(t) is changed to i (t) = 10sin(100pt) A, the peak voltage
across A and B with S closed is
(A) 400V (B) 240V (C) 320V (D) 160V
Common Data Questions: 55 & 56
A system is described by the following state and output equations
( ) ( ) ( ) ( )
( ) ( ) ( )
( ) ( )
( ) ( )
1
1 2
2
2
1
dx t
3x t x t 2u t
dt
dx t
2x t u t
dt
y t x t
where u t is the input and y t is the output
= − + +
= − +
=
i (t)
• A
•
B
S
30W
1 :1
5ms 10ms 15ms 20ms 25ms 30ms t
10A
0
i (t)
10A
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55. The system transfer function is
(A) 2
s 2
s 5s 6
+
+ −
(B) 2
s 3
s 5s 6
+
+ +
(C) 2
s 5
s 5s 6
+
+ +
(D) 2
2s 5
s 5s 6
−
+ −
56. The state transition matrix of the above system is
(A)
3t
2t 3t 2t
e 0
e e e
−
− − −


+
(B)
3t 2t 3t
2t
e e e
0 e
− − −
−
−


(C)
3t 2t 3t
2t
e e e
0 e
− − −
−
+


(D)
3t 2t 3t
2t
e e e
0 e
− −
−
−


Linked Answer Questions: Q.57 to Q.60 Carry Two Marks Each
Statement for Linked Answer Questions: 57 & 58
The figure above shows coils 1 and 2, with dot markings as shown, having 4000
and 6000 turns respectively. Both coils have a rated current of 25A. Coil 1 is
excited with single phase, 400V, 50Hz supply
57. The coils are to be connected to obtain a single phase, 400/1000V, auto
transformer to drive a load of 10kVA. Which of the options given should be
exercised to realize the required auto transformer?
(A) Connect A and D; Common B (B) Connect B and D; Common C
(C) Connect A and C; Common B (D) Connect A and C; Common D
58. In the autotransformer obtained in Question 57, the current in each coil is
(A) Coil-1 is 25 A and Coil-2 is 10 A (B) Coil-1 is 10 A and Coil-2 is 25 A
(C) Coil-1 is 10 A and Coil-2 is 15 A (D) Coil-1 is 15 A and Coil-2 is 10 A
Statement for Linked Answer Questions: 59 & 60
Coil 2
C
D
• •
Coil 1
A
B
+ −
+−
5V
2kW 1kW
2kW
3VAB
B
A
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59. For the circuit given above, the Thevenin’s resistance across the terminals A and
B is
(A) 0.5kW (B) 0.2kW (C) 1kW (D) 0.11kW
60. For the circuit given above, the Thevenin’s voltage across the terminals A and B
is
(A) 1.25V (B) 0.25V (C) 1V (D) 0.5V

SIMBULARA

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Q. No. 1 – 25 Carry One Mark Each
1. The value of the quantity P, where
1
x
0
P= ∫xedx,isequalto
(A) 0 (B) 1 (C) e (D) 1/e
2. Divergence of the three-dimensional radial vector field r is
(A) 3 (B) 1/r (C) ˆi+ˆj+kˆ (D) 3(ˆi +ˆj + kˆ)
3. The period of the signal x(t) 8sin 0.8 t
4
= ⎛⎜ π + π⎞⎟
⎝ ⎠
is
(A) 0.4πs (B) 0.8πs (C) 1.25s (D) 2.5s
4. The system represented by the input-output relationship ( ) ( )
5t
y t x d ,t 0
−∞
= ∫ τ τ > is
(A) Linear and causal (B) Linear but not causal
(C) Causal but not linear (D) Neither linear nor causal
5. The switch in the circuit has been closed for a long time. It is opened at t = 0. At
t = 0+, the current through the 1μF capacitor is
(A) 0A (B) 1A (C) 1.25A (D) 5A
6. The second harmonic component of the periodic waveform given in the figure has
an amplitude of
(A) 0
(B) 1
(C) 2 / π
(D) 5
7. As shown in the figure, a 1Ω resistance is connected across a source that
has a load line v + i = 100. The current through the resistance is
(A) 25A (B) 50A
(C) 100A (D) 200A
5V
1Ω
t=0
1μF 4Ω
+1
0
−1
T /2 T t
Source v
+
−
i
1Ω
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8. A wattmeter is connected as shown in the figure. The wattmeter reads
(A) Zero always
(B) Total power consumed by Z1 and Z2
(C) Power consumed by Z1
(D) Power consumed by Z2
9. An ammeter has a current range of 0 - 5 A, and its internal resistance is 0.2Ω . In
order to change the range to 0 - 25 A, we need to add a resistance of
(A)0.8Ω in series with the meter (B) 1.0Ω in series with the meter
(C)0.04Ω in parallel with the meter (D) 0.05Ω in parallel with the meter
10. As shown in the figure, a negative feedback system has an amplifier of
gain 100 with ±10% tolerance in the forward path, and an attenuator of value
9/100 in the feedback path. The overall system gain is approximately:
(A) 10±1%
(B) 10 ±2%
(C) 10 ±5%
(D) 10 ±10%
11. For the system ( ) 2 ,
s+1
the approximate time taken for a step response to reach 98%
of its final value is
(A) 1s (B) 2s (C) 4s (D) 8s
12. If the electrical circuit of figure (b) is an equivalent of the coupled tank system of
figure (a), then
(A) A, B are resistances and C, D capacitances
(B) A, C are resistances and B, D capacitances
(C) A, B are capacitances and C, D resistances
(D) A, C are capacitances and B, D resistances
Current coil
Potential coil
Wattmeter
1 Z
2 Z
100 ± 10%
9
100
+
−
1 h
2 h A C
B D
(a) Coupled tank (b)Electrical equivalent
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13. A single-phase transformer has a turns ratio of 1:2, and is connected to a purely
resistive load as shown in the figure. The magnetizing current drawn is 1A, and
the secondary current is 1A. If core losses and leakage reactance’s are neglected,
the primary current is
(A) 1.41A (B) 2A (C) 2.24 A (D) 3 A
14. Power is transferred from system A to system B by an HVDC link as shown in the
figure. If the voltages VAB and VCD are as indicated in the figure, and I > 0, then
(A) VAB<0, VCD<0, VAB>VCD (B) VAB>0, VCD>0, VAB>VCD
(C) VAB>0, VCD>0, VAB<VCD (D) VAB>0, VCD<0
15 A balanced three-phase voltage is applied to a star-connected induction motor, the
phase to neutral voltage being V. The stator resistance, rotor resistance referred
to the stator, stator leakage reactance, rotor leakage reactance referred to the
stator, and the magnetizing reactance are denoted by s r s r m r ,r ,x ,x and X ,
respectively. The magnitude of the starting current of the motor is given by
(A)
( ) ( ) 2 2
s r s r
V
r +r + x +x
(B)
( )2 2
s s m
V
r +x +X
(C)
( ) ( ) 2 2
s r m r
V
r +r + X +x
(D)
( )2 2
s m r
V
r +X +x
16. Consider a step voltage wave of magnitude 1pu travelling along a lossless
transmission line that terminates in a reactor. The voltage magnitude across the
reactor at the instant the travelling wave reaches the reactor is
(A) –1pu (B) 1pu (C) 2pu (D) 3pu
1.2
1A
AC
System A
Re ctifier
A
B
AB V
l
CD V
Inverter
AC
System B
C
D
⎯⎯Po⎯wer⎯Flo⎯w ⎯→
A
Reactor
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17. Consider two buses connected by an impedance of (0+j5)Ω. The bus 1 voltage is
100∠30oV , and bus 2 voltage is 100∠0oV. The real and reactive power supplied by
bus 1, respectively, are
(A) 1000W, 268VAr (B) –1000W, –134Var
(C) 276.9W, –56.7Var (D) –276.9W, 56.7Var
18. A three-phase, 33kV oil circuit breaker is rated 1200A, 2000MVA, 3s. The
symmetrical breaking current is
(A) 1200 A (B) 3600 A (C) 35 kA (D) 104.8 kA
19. Consider a stator winding of an alternator with an internal high-resistance
ground fault. The currents under the fault condition are as shown in the figure.
The winding is protected using a differential current scheme with current
transformers of ratio 400/5 A as shown. The current through the operating coil is
(A) 0.17875 A (B) 0.2A (C) 0.375A (D) 60 kA
20. The zero-sequence circuit of the three phase transformer shown in the figure is
(A) (B)
(C) (D)
CT ratio 400 /5 CT ratio 400 /5
(220 + j0)A (250 + j0) A
Operating coil
R
Y
B
r
b
y
R r
G
R r
G
R r
G
R r
G
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21. Given that the op-amp is ideal, the output voltage V0 is
(A) 4V
(B) 6V
(C) 7.5V
(D) 12.12V
22. Assuming that the diodes in the given circuit are ideal, the voltage V0 is
(A) 4V
(B) 5V
(C) 7.5V
(D) 12.12V
23. The power electronic converter shown in the figure has a single-pole double-throw
switch. The pole P of the switch is connected alternately to throws A and B. The
converter shown is a
(A) step-down chopper (buck converter)
(B) half-wave rectifier
(C) step-up chopper (boost converter)
(D) full-wave rectifier
24. Figure shows a composite switch consisting of a power transistor (BJT) in
series with a diode. Assuming that the transistor switch and the diode are
ideal, the I-V characteristic of the composite switch is
(A) (B)
(C) (D)
0 V
10V 10kΩ 15V
10kΩ
10kΩ
IN V
A
P
B
L
+
−
OUT V
+ V
I
−
V
I
V
I
V
I
V
I
R
+2V
2R
+10V
−10V
0 V
−
+
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25. The fully controlled thyristor converter in the figure is fed from a single-phase
source. When the firing angle is 0°, the dc output voltage of the converter is 300
V. What will be the output voltage for a firing angle of 60°, assuming continuous
conduction?
(A) 150V
(B) 210V
(C) 300V
(D) 100πV
Q. No. 26 – 51 Carry Two Marks Each
26. At t = 0, the function ( ) sint
f t has
t
=
(A) a minimum (B) a discontinuity
(C) a point of inflection (D) a maximum
27. A box contains 4 white balls and 3 red balls. In succession, two balls are
randomly selected and removed from the box. Given that the first removed ball is
white, the probability that the second removed ball is red is
(A) 1/3 (B) 3/7 (C) 1/2 (D) 4/7
28. An eigenvector of
1 1 0
P 0 2 2 is
0 0 3
⎛ ⎞
=⎜⎜ ⎟⎟
⎜ ⎟
⎝ ⎠
(A) T ⎡⎣−1 1 1⎤⎦ (B) T ⎡⎣1 2 1⎤⎦ (C) T ⎡⎣1−1 2⎤⎦ (D) T ⎡⎣2 1 −1⎤⎦
29. For the differential equation
2
2
d x dx
6 8x 0
dt dt
+ + = with initial conditions
( )
t 0
dx
x 0 1 and 0
dt =
= = , the solution is
(A) x(t)=2e−6t−e−2t (B) x(t)=2e−2t−e−4t
(C) x(t) = −e−6t +2e−4t (D) x(t)=e−2t +2e−4t
30. For the set of equations, 1 2 3 4 x +2x +x +4x =2 and 1 2 2 4 3x + 6x +3x +12x =6 .
The following statement is true
(A) Only the trivial solution 1 2 3 4 x =x =x =x =0exists
(B) There are no solutions
(C) A unique non-trivial solution exists
(D) Multiple non-trivial solutions exist
+
−
dc V
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31 x(t) is a positive rectangular pulse from t = -1 to t = +1 with unit height as shown
in the figure. The value of | X( ) |2 d {where X( )
∞
−∞
∫ ω ω ω is the Fourier transform of
x(t)} is
(A) 2
(B) 2π
(C) 4
(D) 4π
32. Given the finite length input x[n] and the corresponding finite length output y[n]
of an LTI system as shown below, the impulse response h[n] of the system is
(A) h ⎡⎣n⎤⎦ ={1, 0, 0,1}
↑
(B) h⎡⎣n⎤⎦ ={1,0,1}
↑
(C) h ⎡⎣n⎤⎦ ={1,1,1,1}
↑
(D) h⎡⎣n⎤⎦ ={1,1,1}
↑
33. If the 12Ω resistor draws a current of 1A as shown in the figure, the value of
resistance R is
(A) 4Ω (B) 6Ω (C) 8Ω (D) 18Ω
34. The two-port network P shown in the figure has ports 1 and 2, denoted by
terminals (a, b) and (c, d), respectively. It has an impedance matrix Z with
parameters denoted by ij z .A 1Ω resistor is connected in series with the network at
port 1 as shown in the figure. The impedance matrix of the modified two-port
network (shown as a dashed box) is
(A) 11 12
21 22
z 1 z 1
z z 1
⎛ + + ⎞
⎜ ⎟
⎝ + ⎠
(B) 11 12
21 22
z 1 z
z z 1
⎛ + ⎞
⎜ ⎟
⎝ + ⎠
(C) 11 12
21 22
z 1 z
z z
⎛ + ⎞
⎜ ⎟
⎝ ⎠
(D) 11 12
21 22
z 1 z
z 1 z
⎛ + ⎞
⎜ ⎟
⎝ + ⎠
x(t)
1
−1 0 1 t
h[n]
x[n] = {1,−1}
↑
x [n] = {1,0,0,0, −1}
↑
1Ω
2A
R
1A 12Ω 6V
1Ω a
b
c
d
e
P
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35. The Maxwell's bridge shown in the figure is at balance. The parameters of the
inductive coil are
(A)R=R2R3/R4,L=C4R2R3 (B) 2 3 4 4 2 3 L=RR /R ,R=CRR
(C) ( ) 4 2 3 4 2 3 R=R /RR,L=1CRR (D) ( ) 4 2 3 4 2 3 L=R /RR,R=1/ CRR
36. The frequency response of G(s) =1/⎡⎣s(s+1) (s +2)⎤⎦ plotted in the complex
G(jω) plane (for 0< ω < ∞)is
(A) (B)
(C) (D)
37. The system
1 2 0
x Ax Bu with A , B is
0 2 1
⎡− ⎤ ⎡ ⎤
= + = ⎢ ⎥ =⎢ ⎥
⎣ ⎦ ⎣ ⎦
􀀅
(A) stable and controllable (B) stable but uncontrollable
(C) unstable but controllable (D) unstable and uncontrollable
38. The characteristic equation of a closed-loop system is
s(s+1)(s+3)+k(s+2)=0, k>0. Which of the following statements is true?
(A) Its roots are always real
(B) It cannot have a breakaway point in the range −1<Re⎡⎣s⎤⎦<0
(C) Two of its roots tend to infinity along the asymptotes Re[s] = -1
(D) It may have complex roots in the right half plane
R+jωL 3 R
4 R
2 R
( ) 4 −j / ωC
−3 / 4
Im
Re
ω = 0
−3 / 4
Im
Re
ω = 0
−1/6
Im
Re
ω = 0
−1/6
Im
Re
ω = 0
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39. A 50 Hz synchronous generator is i n i t i a l l y connected to a long lossless
transmission l ine which is open circuited at the receiving end. With
the f i e l d voltage held constant, the generator is disconnected from
the transmission l ine. Which of the following may be said about the
steady state terminal voltage and field current of the generator?
(A) The magnitude of terminal voltage decreases, and the field current does not
change
(B) The magnitude of terminal voltage increases, and the field current does not
change
(C) The magnitude of terminal voltage increases, and the field current increases
(D) The magnitude of terminal voltage does not change, and the field current
decreases
40. A separately excited dc machine is coupled to a 50Hz, three-phase, 4-pole
induction machine as shown in the figure. The dc machine is energized first
and the machines rotate at 1600 rpm. Subsequently the induction machine is
also connected to a 50Hz, three-phase source, the phase sequence being
consistent with the direction of rotation. In steady state,
(A) Both machines act as generators
(B) The dc machine acts as a generator, and the induction machine acts as a
motor
(C) The dc machine acts as a motor, and the induction machine acts as a
generator
(D) Both machines act as motors
41. A balanced star-connected and purely resistive load is connected at the secondary
of a star-delta transformer as shown in the figure. The line-to-line voltage rating of
the transformer is 110V/220V. Neglecting the non-idealities of the transformer, the
impedance 'Z' of the equivalent star-connected load, referred to the primary side of
the transformer, is
Long Transmission Line
receiving end
DC machine Induction machine
4 pole, 50Hz
50Hz, balanced
three − phase supply
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(A) (3+j0)Ω (B) (0.866 − j0.5) Ω (C) (0.866 + j0.5) Ω (D) (1+j0)Ω
42. Consider a three-phase, 50Hz, 11kV distribution system. Each of the conductors is
suspended by an insulator string having two identical porcelain insulators. The self
capacitance of the insulator is 5 times the shunt capacitance between the link and
the ground, as shown in the figure. The voltage across the two insulators is
(A) e1=3.74kV, e2=2.61kV
(B) e1=3.46kV, e2=2.89kV
(C) e1=6.0kV, e2=4.23kV
(D) e1=5.5kV, e2=5.5kV
43. Consider a three-core, three-phase, 50Hz, 11kV cable whose conductors
are denoted as R, Y and B in the figure. The inter-phase capacitance (C1)
between each pair of conductors is 0.2μF and the capacitance between each
l ine conductor and the sheath is 0.4μF . The per-phase charging current is
(A) 2.0A (B) 2.4A (C) 2.7A (D) 3.5A
R
Y
B
R
Y
B
Z
Z Z
r
b
y
4Ω
4Ω
110 /220V
C
5C
5C
e2
e1
Conductor
R
B Y
C1 C1
C2
C2
C1
C2
Outer Sheath
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44. For the power system shown in the figure below, the specifications of the
components are the following:
G1: 25 kV, 100 MVA, X=9%
G2: 25'kV, 100MVA, X=9%
T1: 25 kV/220 kV, 90 MVA, X=12%
T2: 220kV/ 25 kV, 90 MVA, X=12%
Line1: 220 kV, X= 150 ohms
Choose 25 kV as the base voltage at the generator G1, and 200 MVA as
the MVA base. The impedance diagram is
(A)
(B)
(C)
(D)
G1
T1
Line 1
T2
G2
Bus 1 Bus 2
j0.27
j0.18
G1
j0.42 j0.27
j0.18
G2
j0.27
j0.18
G1
j0.62 j0.27
j0.18
G2
j0.27
j0.21
G1
j0.42 j0.27
j0.21
G2
j0.3
j0.21
G1
j0.42 j0.3
j0.21
G2
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45. The transistor circuit shown uses a si l i c o n transistor with
VBE =0.7V,IC ≈IE and a dc current gain of 100. The value of V0 is
(A) 4.65A
(B) 5V
(C) 6.3V
(D) 7.23V
46. The TTL circuit shown in the figure is fed with the waveform X (also shown).
All gates have equal propagation delay of 10 ns. The output Y of the circuit is
(A) (B)
(C) (D)
47. When a "CALL Addr" instruction is executed, the CPU carries out the following
sequential operations internally:
Note: (R) means content of register R
((R)) means content of memory location pointed to by R
PC means Program Counter
SP means Stack Pointer
(A) (SP) incremented (B) (PC) ← Addr
( )
(( )) ( )
PC Addr
SP PC
←
←
(( )) ( )
( )
SP PC
SP incremented
←
(C) (PC) ← Addr (D) ((SP)) ← (PC)
( )
(( )) ( )
SP incremented
SP ← PC
( )
( )
SP incremented
PC ← Addr
+10V
10kΩ 50kΩ
0 V
100Ω
100 ns
X
1
0 t
X Y
Y
1
0 t
Y
1
0 t
Y
1
0 t
Y
1
0 t
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Common Data Questions: 48 & 49
A separately excited DC motor runs at 1500 rpm under no-load with 200 V applied
to the armature. The field voltage is maintained at its rated value. The speed of
the motor, when it delivers a torque of 5 Nm, is 1400 rpm as shown in the figure.
The rotational losses and armature reaction are neglected.
48. The armature resistance of the motor is,
(A)2Ω (B) 3.4Ω (C) 4.4Ω (D) 7.7Ω
49. For the motor to deliver a torque of 2.5 Nm at 1400 rpm the armature voltage to
be applied is
(A) 125.5V (B) 193.3V (C) 200V (D) 241.7V
Common Data Questions: 50 & 51
Given f(t) and g(t)as shown below:
50. g(t)can be expressed as
(A) g(t)=f(2t−3) (B) ( ) t
g t f 3
2
= ⎛⎜ − ⎞⎟
⎝ ⎠
(C) ( ) 3
g t f 2t
2
= ⎛⎜ − ⎞⎟
⎝ ⎠
(D) ( ) t 3
g t f
2 2
= ⎛⎜ − ⎞⎟
⎝ ⎠
51. The Laplace transform of g(t) is
(A) ( 3s 5s) 1
e e
s
− (B) ( 5s 3s) 1
e e
s
− − −
(C) ( ) 3s
2s e
1 e
s
−
− − (D) ( 5s 3s) 1
e e
s
−
speed (rpm)
1500
1400
0 5 torque (Nm)
f(t)
1
0 1 t
g(t)
1
0
3 5 t
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Linked Answer Questions: Q.52 to Q.55 Carry Two Marks Each
Statement for Linked Answer Questions: 52 & 53
The following Karnaugh map represents a function F.
52. A minimized form of the function F is
(A) F=XY+YZ (B) F=XY+YZ (C) F=XY+YZ (D) F=XY+YZ
53. Which of the following circuits is a realization of the above function F?
(A)
(B)
(C)
(D)
Statement for Linked Answer Questions: 54 & 55
The L-C circuit shown in the figure has an inductance L=1mH and a
capacitanceC=10μF.
X
Y
Z
F
X
Y
Z
F
X
Y
Z
F
X
Y
Z
F
L
t=0
C
i
100V
−
+
1 1 1 0
1 0 0 1 0
0
F 00 01 11 10
X
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54. The initial current through the inductor is zero, while the initial capacitor voltage is
100 V. The switch is closed at t = 0. The current i through the circuit is:
(A) 5cos(5×103t)A (B) 5sin(104t)A
(C) 10 cos(5 ×103 t)A (D) 10 sin(104 t) A
55. The L-C circuit of Q54 is used to commutate a thyristor, which is initially carrying
a current of 5A as shown in the figure below. The values and initial conditions of L
and C are the same as in Q54. The switch is closed at t = 0. If the forward drop is
negligible, the time taken for the device to turn off is
(A) 52μs (B) 156μs (C) 312μs (D) 26μs
General Aptitude (GA) Questions
Q.No. 56-60 Carry One Mark Each
56. 25 persons are in a room. 15 of them play hockey, 17 of them play football and
10 of them play both hockey and football. Then the number of persons playing
neither hockey nor football is
(A) 2 (B) 17 (C)13 (D) 3
57. The question below consists of a pair of related words followed by four pairs of
words. Select the pair that best expresses the relation in the original pair.
Unemployed: Worker
(A) fallow: land (B) unaware: sleeper (C) wit: jester (D) renovated: house
58. Choose the most appropriate word from the options given below to complete the
following sentence
If we manage to ____________ our natural resources, we would leave a better
planet for our children.
(A) uphold (B) restrain (C) cherish (D) conserve
59. Which of the following options is closest in meaning to the word: Circuitous?
(A) cyclic (B) indirect (C) confusing (D) crooked
L
t=0
C
i
100V
−
+
100V 5A 20Ω
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60. Choose the most appropriate word from the options given below to the complete
the following sentence:
His rather casual remarks on politics ___________ his lack of seriousness about
the subject.
(A) masked (B) belied (C) betrayed (D)suppressed
Q.No. 61 - 65 Carry Two Marks Each
61. Hari (H), Gita (G), Irfan (I) and Saira (S) are siblings (i.e. brothers and sisters).
All were born on 1st January. The age difference between any two successive
siblings (that is born one after another) is less than 3 years. Given the following
facts:
i. Hari’s age + Gita’s age > Irfan’s age + Saira’s age
ii. The age difference between Gita and Saira is 1 year. However Gita is not the
oldest and Saira is not the youngest.
iii. There are no twins.
In what order were they born (oldest first)?
(A) HSIG (B) SGHI (C) IGSH (D) IHSG
62. 5 skilled workers can build a wall in 20days; 8 semi-skilled workers can build a wall
in 25 days; 10 unskilled workers can build a wall in 30days. If a team has 2 skilled,
6 semi-skilled and 5 unskilled workers, how long will it take to build the wall?
(A) 20 (B) 18 (C) 16 (D) 15

63. Modern warfare has changed from large scale clashes of armies to suppression of
civilian populations. Chemical agents that do their work silently appear to be
suited to such warfare; and regretfully, there exist people in military
establishments who think that chemical agents are useful tools for their cause.
Which of the following statements best sums up the meaning of the above passage:
(A) Modern warfare has resulted in civil strife.
(B) Chemical agents are useful in modern warfare.
(C) Use of chemical agents in warfare would be undesirable
(D) People in military establishments like to use chemical agents in war.

64. Given digits 2,2,3,3,4,4,4,4 how many distinct 4 digit numbers greater than 3000
can be formed?
(A) 50 (B) 51 (C) 52 (D) 54

65. If 137+276=435 how much is 731+672?
(A) 534 (B) 1403 (C) 1623 (D)1513