Electrical Machines If an additional resistance is connected in series with a DC motor operating at rated speed, the speed of the motor will Remain unaltered. Oscillate around the normal speed. Increase. Reduce. Remain unaltered. Oscillate around the normal speed. Increase. Reduce. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If field current is decreased in shunt dc motor, the speed of the motor increases. None of these decreases. remains same. increases. None of these decreases. remains same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a 3-phase, 4 pole, 50 Hz synchronous motor the frequency, pole number and the frequency are halved. The motor speed will be 3000 rpm 75 rpm 375 rpm 1500 rpm 3000 rpm 75 rpm 375 rpm 1500 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A series generator is connected in series to a feeder having 0.5Ω resistance to boost the voltage. The induced voltage is given by Eg = 0.6Ia, Ra = 0.2Ω and Rs = 0.3Ω. Find the voltage boosted by the generator, when delivering 400 Amp? 60 V. 30 V. 90 V. 40 V. 60 V. 30 V. 90 V. 40 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has the highest power factor at full load? Capacitor run Shaded pole Resistance split phase Capacitor start Capacitor run Shaded pole Resistance split phase Capacitor start ANSWER DOWNLOAD EXAMIANS APP