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| 1 |
A hydraulic turbine having rated speed of 250
rpm is connected to a synchronous generator. In order to produce
power at 50 Hz, the number of poles required in the generator are |
| Options |
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| Correct Answer |
D |
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| 2 |
For the equation x(t)+3 x(t) +2x(t) = 5, the
solution x (t) approaches which of the following values as t ® ¥ ? |
| Options |
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| Correct Answer |
B |
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| 3 |
The following motor definitely has a permanent
magnet rotor |
| Options |
| A) DC commutator motor |
B) Brushless dc motor
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| C) Stepper motor |
D) Reluctance motor |
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| Correct Answer |
C |
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| 4 |
A110 kV, single core coaxial, XLPE insulated
power cable delivering power at 50Hz, has a capacitance of 125 nF/km.
If the dielectric loss tangent of XLPE is 2 x 10-4, the
dielectric power loss in this cable in W/km is |
| Options |
| A) 5.0 |
B) 31.7
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| C) 37.8 |
D) 189.0 |
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| Correct Answer |
D |
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| 5 |
The simultaneous application of signals x(t)
and y(t) to the horizontal and vertical plates, respectively, of an
oscilloscope, produces a vertical figure-of-8 display. If P and Q
are constants, and x(t) = P sin (4t + 30), then y(t) is equal to |
| Options |
| A) Q sin (4t - 30) |
B) Q sin (2t + 15)
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| C) Q sin (8t + 60) |
D) Q sin (4t + 30) |
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| Correct Answer |
B |
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| 6 |
A 500 MW 3-phase Y-connected synchronous
generator has a rated voltage of 21.5 kV at 0.85pf. The line current
when operating at full load rated conditions will be |
| Options |
| A) 13.43 kA |
B) 15.79 kA
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| C) 23.25 kA |
D) 27.36 kA |
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| Correct Answer |
B |
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| 7 |
Total instantaneous power supplied by a 3-phase ac supply to a
balanced R-L load is
|
| Options |
| A) zero |
B) constant
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| C) pulsating with zero average |
D) pulsating with non-zero average |
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| Correct Answer |
B |
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| 8 |
The equivalent circuit of a transformer has
leakage reactances X1 , X |
| Options |
| A) X1>> X |
B) X1<< X |
| C) X1» X |
D) X1» X |
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| Correct Answer |
D |
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| 9 |
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
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B) Probability (P 
Q ) 
Probability (P) + Probability (Q)
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C) If P and Q are mutually exclusive, then they
must be independent
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D) Probability (P 
Q ) 
Probability (P)
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| Correct Answer |
D |