Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 3.5+j5.8 ohms 53+j85 ohms 3.05+j5.08 ohms 8+j13 ohms 3.5+j5.8 ohms 53+j85 ohms 3.05+j5.08 ohms 8+j13 ohms ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50Hz, the emf in the rotor will have a frequency of 1.5Hz 48.5Hz 2.5Hz 51.5Hz 1.5Hz 48.5Hz 2.5Hz 51.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? 16.55 Nm 15.28 Nm 15.6 Nm Zero 16.55 Nm 15.28 Nm 15.6 Nm Zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the operating region of slip in a 1-phase induction motor? -2 < S < 2 -1 < S < 1 0 < S < 2 0 < S < 1 -2 < S < 2 -1 < S < 1 0 < S < 2 0 < S < 1 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Alternator operates on the principle of self or mutual induction. mutual induction. self induction. electromagnetic induction. self or mutual induction. mutual induction. self induction. electromagnetic induction. 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, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP