Electrical Machines In salient pole synchronous machine, maximum power occurs at a load angle of 0° 90° less than 90° Greater than 90° 0° 90° less than 90° Greater than 90° ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a single phase transformer the magnitude of leakage reactance is twice that of resistance of both primary and secondary. With secondary short circuited, the input power factor is 2/√5 1/√2 1/√5 1/3 2/√5 1/√2 1/√5 1/3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side lags by -30°. Star side lags by -30°. Star side leads by 30°. Delta side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Star side leads by 30°. Delta side leads by 30°. 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, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.9 Ω 15.1 Ω 31.9 Ω 31.1 Ω 15.9 Ω 15.1 Ω 31.9 Ω 31.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Normally for the design of transformer the ambient temperature is taken as 35°C. 45°C. 27°C. 32°C. 35°C. 45°C. 27°C. 32°C. ANSWER DOWNLOAD EXAMIANS APP