(a) generator motor (c) transformer (d) (a) and (b) both (e) (a) or (b)
(a) the laminations are think (b) number of turns in the primary winding is reduced (c) the number of turns in the secondary winding is reduced the laminations are thin
(a) zero (b) 1500 r.p.m. infinity (d) 3000 r.p.m. (e) none of the above
(a) 1 Hz square wave 1 Hz sinusoidal voltage (c) d.c. voltage (d) none of the above
(a) to change alternating current to a direct current (b) to improve commutation (c) for easy control to change alternating voltage to direct voltage
(a) true false
true (b) false
(a) increasing the rotor reactance increasing the rotor resistance (c) increasing the stator resistance (d) none of the above
proportional to slip (b) inversely proportional to slip (c) proportional to the square of the slip (d) none of the above
(a) single phase motor two phase motor (c) a.c series motor (d) none of the above
(a) wave winding lap winding (c) simplex lap winding (d) none of the above
(a) the reactance of the rotor is half of the resistance (b) the reactance of the rotor is twice of the rotor resistance the reactance of the rotor is equal to the rotor resistance (d) none of the above
(a) by interchanging supply terminals by interchanging field terminals (c) either (a) or (b) (b)none of above
(a)the resistance of armature is high. (b) field current is not sufficiently high. there is no residual magnetism. (d) field winding has small number of turns.
By increasing the radius of the conductor (b) By decreasing the radius of the conductor (c) By increasing the frequency of the supply (d) If the hollow conductor is used (e) (b) and (d) both
Burn as the eddy currents in the field produce heat (b) Run at its normal speed (c) Run at a lower speed (d) Run continuously but the sparking takes place at the burshes
(a) The speed of the motor will be reduced (b) It will continue to run at its normal speed The speed of the motor will be enormously high and might destroy itself (d) The current in the armature will increase
(a) true false
(a) Clockwise when looking at the front end of the motor Counter-clockwise when looking at the front end of the motor
lagging (b) leading (c) unity (d) more than unity
MCQ of Transformer page-20:91. All day efficiency of a distribution transformer is ………. its commercial efficiency.
MCQ of Transformer page-19:81. Which of the following is not a fitting on the transformer ?
MCQ of Transformer page-18:71. The short circuit test on a transformer gives its