Electrical Machines Ward Leonard control provides speed control above rated speed. below rated speed. in both direction. in one direction only. above rated speed. below rated speed. in both direction. in one direction only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pole pairs Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance for lap-winding ? PZL/ 4Sa PZL/4S PZL/4SP² PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4SP² PZL/4Sa² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An inverted V curve of synchronous motor shows variation of power factor and DC excitation at constant load. supply voltage and excitation current at constant load. power factor and supply voltage during hunting. supply voltage and field current at constant excitation. power factor and DC excitation at constant load. supply voltage and excitation current at constant load. power factor and supply voltage during hunting. supply voltage and field current at constant excitation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 400 V, 50 Hz, 30 Hp, three phase IM is drawing 50 A current at 0.8 p.f lagging. The stator and rotor copper losses are 1.5 KW and 900 W respectively. The friction and windage losses are 1050 W and core losses are 1200 W. The air gap power of the motor will be 24.11 kW. 23.06 kW. 26.21 kW. 25 kW. 24.11 kW. 23.06 kW. 26.21 kW. 25 kW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines R1 is the resistance of the primary winding of the transformer. The turn ratio in terms of primary to secondary is K. Then the equivalent resistance of the primary referred to secondary is K²R1 R1 /K² R1 /K K×R1 K²R1 R1 /K² R1 /K K×R1 ANSWER DOWNLOAD EXAMIANS APP
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