No. |
Question |
1 |
For the scalar field u =
+
, magnitude of the gradient at the point (1,3) is |
Options |
|
Correct Answer |
C |
|
2 |
A digital-to-analog converter with a full-scale
output voltage of 3.5 V has a resolution close to 14m V. Its bit size is |
Options |
|
Correct Answer |
B |
|
3 |
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 |
Options |
A) 339 rpm |
B) 359 rpm |
C) 366 rpm |
D) 386 rpm |
|
Correct Answer |
C |
|
|
4 |
In relation to the synchronous machines, which
one of the following statements is false? |
Options |
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 |
|
Correct Answer |
C |
|
5 |
The 8085 assembly language instruction that
stores the content of H and L registers into the memory locations 2050H
and 2051H, respectively, is
|
Options |
A) SPHL 2050H |
B) SPHL2051H |
C) SHLD 2050H |
D) STAX 2050H
|
|
Correct Answer |
C |
|
6 |
If
is the electric field intensity, �(� x
) is equal to |
Options |
A)
|
B) |
| |
C) null vector |
D) zero |
|
Correct Answer |
D |
|
7 |
For the function f(x) = x2 e-x,
the maximum occurs when x is equal to |
Options |
|
Correct Answer |
B |
|
8 |
Two wattmeters, which are connected to measure
the total power on a three -phase system supplying a balanced load, read
10.5 kW and - 2.5 kW, respectively. The total powere and the power
factor, respectively, are |
Options |
A) 13.0 kW, 0.334 |
B) 13.0 kW, 0.684
|
C) 8.0 kW, 0.52 |
D) 8.0 kW, 0.334 |
|
Correct Answer |
D |
|
9 |
The insulation strength of an EHV transmission
line is mainly governed by |
Options |
A) load power factor |
B) switching over-voltages
|
C) harmonics |
D) corona |
|
Correct Answer |
B |
|
10 |
For the equation,
s3 - 4s2+ s + 6 = 0
the number of roots in the left half of s-plane will be |
Options |
A) zero |
B) one
|
C) two |
D) three
|
|
Correct Answer |
C |
|
11 |
A dc potentiometer is designed to measure up to
about 2 V with a slide wire of 800 mm. A standard cell of emf 1.18 V
obtains balance at 600 mm. A test cell is seen to obtain balance at 680
mm. The emf of the test cell is |
Options |
A) 1.00V |
B) 1.34V
|
C) 1.50V |
D) 1.70V
|
|
Correct Answer |
B |
|
12 |
High Voltage DC (HVDC) transmission is mainly
used for
|
Options |
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
|
|
Correct Answer |
A |
|
13 |
A bipolar junction transistor (BJT) is used as a
power control switch by biasing it in the cut-off region (OFF state) or
in the saturation region (ON state). In the ON state, for the BJT |
Options |
A) both the base-emitter and base-collector junctions
are reverse biased |
B) the base-emitter junction is reverse biased, and
the base-collector junction is forward biased |
C)
the base-emitter junction is forward biased, and the
base-collector junction is reverse biased |
D) both the base-emitter and base-collector junctions
are forward biased |
|
Correct Answer |
D |
|
14 |
The Q - meter works on the principle of |
Options |
A) mutual inductance |
B) self inductance
|
C) series resonance |
D) parallel resonance |
|
Correct Answer |
C |
|
15 |
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 |
Options |
A) 1204 MW |
B) 1504 MW |
C) 2085 MW |
D) 2606 MW |
|
Correct Answer |
C |
|
16 |
If the following program is executed in a
icroprocessor, the number of instruction cycles it will take from START
to HALT is
START MVI A, 14H ; Move 14H to register A
SHIFT RLC ; Rotate left without carry
JNZ SHIFT ; Jump on non-zero to SHIFT
HALT |
|
Options |
|
Correct Answer |
C |
|
17 |
A moving iron ammeter produces a full scale
torque of 240 mNm with a deflection of 120�
at a current of 10 A. The rate of change of self inductance (mH/radian)
of the instrument at full scale is |
Options |
A) 2.0 mH/radian |
B) 4.8 mH/radian |
C) 12.0 mH/radian |
D) 114.6 mH/radian |
|
Correct Answer |
B |
|
18 |
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 |
Options |
A) 0.85 |
B) 1.00
|
C) 0.80 lag |
D) 0.90 lag |
|
Correct Answer |
C |
|
19 |
The conduction loss versus device current
characteristic of a power MOSFET is best approximated by |
Options |
A) a parabola
|
B) a straight line
|
C) a rectangular hyperbola
|
D) an exponentially decaying function |
|
Correct Answer |
A |
|
20 |
If P and Q are two random events, then the
following is TRUE
|
Options |
A) Independence of P and Q implies that probability
(P
Q ) = 0
|
B) Probability (P
Q )
Probability (P) + Probability (Q)
|
C) If P and Q are mutually exclusive, then they must
be independent
|
D) Probability (P
Q )
Probability (P)
|
|
Correct Answer |
D |