# A power station consists of two synchronous generators A and B of rating 250 MVA and 500 MVA with inertia 1.6 p.u. and 1 p.u. respectively on their own base MVA ratings. The equivalent : P.U inertia for the system on 100 MVA common base will be

1.  2.6

2.  0.615

3.  1.625

4.   9.0

4

9.0

Explanation :
No Explanation available for this question

# An alternator having induced end of 1.6 p.u. is connected to an infinite bus of 1.0 p.u. If the bus has reactance of 0.6 p.u. and alternator has reactance of 0.2 p.u., the maximum power that can be transferred is given by

1.  8 p.u.

2.  2. p.u.

3.  2.67 p.u.

4.  5.0 P.u.

4

2. p.u.

Explanation :
No Explanation available for this question

# The per unit impedance of a circuit element 0.15. If the base kV and base MVN A are halved then the new value of the per unit impedance of the circuit element will he

1.  0.075

2.  0.15

3.  0.30

4.  0.600

4

0.30

Explanation :
No Explanation available for this question

# The velocity of travelling wave through a cable at relative permittivity 9 is

1.  9 x 108 metre/sec

2.  3 x108 metre/sec

3.  108 metre/sec

4.   2 x108 metre/sec

4

108 metre/sec

Explanation :
No Explanation available for this question

# A 66 kV system has string insulator having five discs and the earth to disc capacitance ratio at 0.10. The string efficiency will be

1.  89%

2.  75%

3.  67%

4.  55%

4

67\%

Explanation :
No Explanation available for this question

# A voltage of 1000 kV is applied to an overhead line with its receiving end open. If the surge impedance of the line is 500 ohm, then the total surge power in the line is

1.  2000 MW

2.  500 MW

3.  2 MW

4.   0.5 MW

4

2000 MW

Explanation :
No Explanation available for this question

# The main criterion for selection of the size of a distribution for a radial distribution system is

1.  voltage drop

2.  corona loss

3.  temperature rise

4.   capital cost

4

voltage drop

Explanation :
No Explanation available for this question

# If an induction machine is run at above synchronous speed, it acts as

1.  a synchronous motor

2.  an indcution generator

3.  an inductor motor

4.  none of these

4

an indcution generator

Explanation :
No Explanation available for this question

# The low voltage winding of a 400/230. V, 1-phase, 50 Hz transformer is to be connected to a 25 Hz, the supply voltage should be

1.  230 V

2.  460 V

3.  115 V

4.  65 V

4

115 V

Explanation :
No Explanation available for this question

# Three phase transformers which cannot be connected in parallel are

1.  YY with ΔΔ

2.  Y Δ with Δ Y

3.  YY with YΔ

4.  none of these

4