2 A single-phase half-controlled
rectifier is driving a separately excited dc motor. The dc motor has a back emf
constant of 0.5 V/rpm. The armature current is 5 A without any ripple. The
armature resistance is 2W. The converter is working from a 280 V, single phase
ac source with a firing angle of 80°. Under this operating condition, the speed
of the motor will be
A) 339 rpm
B) 359 rpm
C) 366 rpm
D) 386
rpm
Answer : (C)

3 In relation to the synchronous machines,
which one of the following statements is false?
A) In salient pole
machines, the direct-axis synchronous reactance is greater than the
quadrature-axis synchronous reactance
B) The damper bars help the synchronous
motor self start
C) Short circuit ratio is the ratio of the field current
required to produce the rated voltage on open circuit to the rated armature
current
D) The V-curve of a synchronous motor represents the variation in
the armature current with field excitation, at a given output power
Answer
: (C)

4 A parallel plate air-filled capacitor has plate area of
l0-4 m2 and plate separation of 10-3 m. It is connected to a 0.5 V, 3.6 GHz
source. The magnitude of the displacement current is (e0 = 1/36p x 10-9 F/m)

A) 10 mA
B) 100 mA
C) 10 A
D) 1.59 mA
Answer :
(A)

5 The 8085 assembly language instruction that stores the
content of H and L registers into the memory locations 2050H and 2051H,
respectively, is
A) SPHL 2050_H
B)
SPHL2051_H
C) SHLD 2050_H
D) STAX
2050_H
Answer : (C)

6 If E is the electric field
intensity, Ñ(Ñ x E ) is equal to
A) E
B) | E |
C) null vector

D) zero
Answer : (D)

7 The insulation strength of an EHV
transmission line is mainly governed by
A) load power factor
B)
switching over-voltages
C) harmonics
D) corona
Answer :
(B)

8 The Q - meter works on the principle of
A) mutual
inductance
B) self inductance
C) series resonance
D) parallel
resonance
Answer : (C)

9 A 800 kV transmission line is
having per phase line inductance of 1.1 mH/km and per phase line capacitance of
11.68 nF/km. Ignoring the length of the line, its ideal power transfer
capability in MW is
A) 1204 MW
B) 1504 MW
C) 2085 MW
D) 2606
MW
Answer : (C)

10 In a PCM system, if the code word length
is increased from 6 to 8 bits, the signal to quantization noise ratio improves
by the factor
A) 8/6
B) 12
C) 16
D) 8
Answer :
(C)

11 At an industrial sub-station with a 4 MW load, a capacitor
of 2 MVAR is installed to maintain the load power factor at 0.97 lagging. If the
capacitor goes out of serivce, the load power factor becomes
A) 0.85

B) 1.00
C) 0.80 lag
D) 0.90 lag
Answer : (C)

12
The conduction loss versus device current characteristic of a power MOSFET is
best approximated by
A) a parabola
B) a straight line
C) a
rectangular hyperbola
D) an exponentially decaying function
Answer :
(A)

13 High Voltage DC (HVDC) transmission is mainly used for

A) bulk power transmission over very long distances
B)
inter-connecting two systems with the same nominal frequency
C) eliminating
reactive power requirement in the operation
D) minimizing harmonics at the
converter stations
Answer : (A)

14 For the equation,
s3 -
4s2+ s + 6 = 0
the number of roots in the left half of s-plane will
be

A) 0
B) 1
C) 2
D) 3
Answer : (C)

15
For the function f(x) = x2 e-x, the maximum occurs when x is equal to
A)
2
B) 1
C) 0
D) -1
Answer : (B)