Electrical Machines Which of the following machines have highest power factor with respect to magnetizing current? Semi closed slot type machine. Any of the above. Closed slot type machines. Open slot type machines. Semi closed slot type machine. Any of the above. Closed slot type machines. Open slot type machines. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When applied rated voltage per phase is reduce to one half, the starting torque of three phase squirrel cage induction motor becomes 1/2 of the initial value 4 time the initial value twice the initial value 1/4 of the intial value 1/2 of the initial value 4 time the initial value twice the initial value 1/4 of the intial value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor copper loss? 40W 100W 80W 60W 40W 100W 80W 60W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Resistance commutation is used generally in case of None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. None of these DC machines above 10 kW. DC machines bellow 5 kW. fractional kW DC machines. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as crawling. relative speed. air gap. cogging. crawling. relative speed. air gap. cogging. ANSWER DOWNLOAD EXAMIANS APP
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