Electrical Machines A dc shunt generator has full-load voltage regulation of 10% at rated speed of 1000 rpm. If it is now driven at 1250 rpm, then its voltage regulation at full load would be less than 10% remain unchanged be more than 10% be 12.5% be less than 10% remain unchanged be more than 10% be 12.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 V DC generator in run at rated speed with no excitation. The open circuit voltage will be 250 V. zero. about 100 V. very small, say about 2 or 3 V. 250 V. zero. about 100 V. very small, say about 2 or 3 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When excitation is increased (over excitation), the synchronous generator operates at leading power factor. lagging power factor. unity power factor. any of the above. leading power factor. lagging power factor. unity power factor. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The air gap between stator and the rotor of the 3 - φ induction motor is kept depends on the material of stator and the rotor. air gap does not matter. as wide as possible. as small as possible. depends on the material of stator and the rotor. air gap does not matter. as wide as possible. as small as possible. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC shunt motor if load is increased, the speed increased slightly. reduce slightly. remains constant. increase proportional. increased slightly. reduce slightly. remains constant. increase proportional. ANSWER DOWNLOAD EXAMIANS APP