# For a load flow solution the quantities normally specified at a voltage controlled bus are

1.  P and Q

2.  P and V

3.  Q and V

4.  P and δ

4

P and δ

Explanation :
No Explanation available for this question

# In a synchronous machine, in case the axis of field flux in line with the armature flux, the machine is working

1.  As synchronous motor

2.  As synchronous generator

3.  As floating machine

4.  The machine will not work

4

As floating machine

Explanation :
No Explanation available for this question

# An ideal voltage source is connected across a variable resistance. The variation of current as a function of resistance is given by

1.  A straight line passing through the origin

2.  A rectangular hyperbola

3.  A parabola

4.  All of the above

4

A rectangular hyperbola

Explanation :
No Explanation available for this question

# Pure inductive circuit takes power (reactive) from the a.c line when

1.  Both applied voltage and current rise

2.  Both applied voltage and current decrease

3.  Applied voltage decreases but current increases

4.  None of the above

4

Both applied voltage and current decrease

Explanation :
No Explanation available for this question

# An alternator has a phase sequence of RYB for its phase voltage. In case of field current is reversed, the phase sequence will become

1.  RBY

2.  RYB

3.  YRB

4.  none of these

4

RYB

Explanation :
No Explanation available for this question

# A synchronous generator connected to an infinite bus delivers at a lag p.f. If its excitation is increased

1.  The terminal voltage increases

2.  Voltage angle δ increases

3.  Current delivered increases

4.  All of these

4

Current delivered increases

Explanation :
No Explanation available for this question

# A motor is receiving 25% of the power that it is capable of receiving from an infinite bus. If load of the motor is doubled, then maximum value of δ during swinging of the rotor around its new equilibrium position will be

1.  400

2.     >300

3.

4.       250

4

>300

Explanation :
No Explanation available for this question

# A 10 kVA, 400 V/200 V single phase transformer with 10% impedance draws a steady short circuit line current of

1.  50 A

2.   150 A

3.     250 A

4.  350 A

4

150 A

Explanation :
No Explanation available for this question

# The percentage resistance and percentage reactance of a 10 kVA, 400 V/200 V, 3- phase transformer are 2 % and 10 % respectively. If the constant losses in the machine are 1 %, the maximum percentage efficiency of the transformer is

1.  98.32

2.     97.25

3.  96.85

4.    96.12

4

96.85

Explanation :
No Explanation available for this question

# It x is the system reactance and r is its resistance, the power transferred is maximum when

1.    x =  r

2.         x = √2 r

3.       x = √3 r

4.  x = 2 r

4