# An alternator at 300 kW is driven by a prime mover of speed regulation 4% and another alternator of 220 kW driven by a prime mover of speed regulation 3%. The total load they can take is

1.  500 kW

2.  567 kW

3.  425 kW

4.  257 kW

4

425 kW

Explanation :
No Explanation available for this question

# The severity of line to ground arid 'three Phase faults at the terminals of an unloaded synchronous generator is to be same.If the terminal voltage is 1.0 p.u. and Z1=Z2=j 0.1-p.u.Z0 =-j. 0.05 p.u.for the alternator, their the required inductive reactance for neutral grounding is

1.  0.0166 p.u

2.  0.05 p.u

3.  0.1 p.u.

4.  0.15 p.u

4

0.0166 p.u

Explanation :
No Explanation available for this question

# In a three phase font wire system, Currents in the lines a, b and c under ,abnormal conditions are as follows Ia=10030o Ib=50?200o Ic=?300o The positive sequence currents in line a will be

1.  18.97A

2.  32.18 A

3.  27.97 A

4.  25 A

4

32.18 A

Explanation :
No Explanation available for this question

# The line to ground. voltage on the, High Voltage side of a step up transformer are 100 kV, 33 kV and 38 kV on phases a, b and a respectively. If voltage of phase a leads that of phase, b' by,1000 and lags that of phase e by 176.5%, then positive and negative components of phase voltage are

1.   (50.65 + j14.32), (30.55 + j4.26)

2.  (50.65 + j14.32), (30.55 - j4.26)

3.  (50.65 - j14.32), (18.79 + j10)

4.  (50.65 + j14.32), (18.79 - j10.0)

4

(50.65 + j14.32), (30.55 - j4.26)

Explanation :
No Explanation available for this question

# If normal frequency is 50 Hz, then setting of the under-frequency relay for the most important load could be

1.  49 Hz

2.  48.5 Hz

3.  47.5 Hz

4.  there is no grading for under frequency relays

4

there is no grading for under frequency relays

Explanation :
No Explanation available for this question

# The relay which is most sensitive to power swings (maloperation) is

1.  mho relay

2.  reactance relay

3.  impedance relay

4.  all are equally affected

4

impedance relay

Explanation :
No Explanation available for this question

# Maximum value of the restriking voltage across contents of the circuit breaker is

1.  215.56 kV

2.  208.56 kV

3.  186.0 kV

4.  100 kV

4

215.56 kV

Explanation :
No Explanation available for this question

# A thyrite type lightning arrestor

1.  blocks surge voltage appearing in a line

2.  absorbs surge voltage appearing in a line

3.  offers a low resistance path to the surge appearing in the line

4.  returns surge back to the source

4

offers a low resistance path to the surge appearing in the line

Explanation :
No Explanation available for this question

# The use of fast-acting relays and circuit breakers for clearing a sudden short-circuit on a transmission link between a generator and the receiving-end bus improves transient stability of the machine because

1.  short-circuit current becomes zero

2.  post-fault transfer impedance attains a value higher than that during the fault

3.  ordinate of the post-fault power-angle characteristic is higher than that of during fault characteristic

4.  voltage behind the transient reactance increases to a higher value

4

post-fault transfer impedance attains a value higher than that during the fault

Explanation :
No Explanation available for this question

# A line trap in carrier current relaying tuned to carrier frequency presents

1.  high impedance to carrier frequency but low impedance to power frequency

2.  low impedance to both carrier and power frequency

3.  high impedance to both carrier and power frequency

4.  low impedance to carrier frequency but high impedance to power frequency

4