Electrical Machines If field current is decreased in shunt dc motor, the speed of the motor remains same. decreases. increases. None of these remains same. decreases. increases. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 1, 2, 3 2, 3, 4, 5 2, 3, 4 2, 3 ,5 1, 2, 3 2, 3, 4, 5 2, 3, 4 2, 3 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the handle of a three point starter goes to back to OFF position, it may be due to all of these. high filed circuit resistance. zero or very low voltage supply. over load. all of these. high filed circuit resistance. zero or very low voltage supply. over load. 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 R1 /K² R1 /K K×R1 K²R1 R1 /K² R1 /K K×R1 K²R1 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.45 Ω. 0.78 Ω. 0.24 Ω. 0.66 Ω. 0.45 Ω. 0.78 Ω. 0.24 Ω. 0.66 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on which of the following? Rotor speed. Shaft torque. Core loss component. Synchronous speed. Rotor speed. Shaft torque. Core loss component. Synchronous speed. ANSWER DOWNLOAD EXAMIANS APP