Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 28 W. 30 W. 25 W. 36 W. 28 W. 30 W. 25 W. 36 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 12 pole, 600 V, 50 Hz star connected IM has rotor resistance and stand still resistance of 0.03 Ω and 0.5 Ω respectively. The speed of maximum torque will be 540 rpm. 450 rpm. 470 rpm. 240 rpm. 540 rpm. 450 rpm. 470 rpm. 240 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If residual magnetism of a shunt generator is destroyed accidentally it may be restored by connecting its shunt field to a DC source. in reverse. to an AC source. to earth. to a DC source. in reverse. to an AC source. to earth. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following windings are necessary in case of all dc machines? wave winding open type winding lap winding closed winding wave winding open type winding lap winding closed winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 KVA transformer has iron loss of 150 W and full load copper loss of 250 W. The maximum efficiency of the transformer would occur when the total loss is 300 W 250 W 500 W 400W 300 W 250 W 500 W 400W 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 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP