Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 2.2 Ω 5.7 Ω 6 Ω 1.9 Ω 2.2 Ω 5.7 Ω 6 Ω 1.9 Ω 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 1/4 of the intial value twice the initial value 1/2 of the initial value 4 time the initial value 1/4 of the intial value twice the initial value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC motors has almost constant speed over their full load range? Compound (cummolative). Series. Shunt. none of these. Compound (cummolative). Series. Shunt. none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 3 2, 4 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting in a synchronous motor takes place motor is under loaded. when supply voltage fluctuates. when power factor is unity. when load varies. motor is under loaded. when supply voltage fluctuates. when power factor is unity. when load varies. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type motors are preferred for lathes? Squirrel Cage induction motor. Either A or B. DC shunt motors. Synchronous motor. Squirrel Cage induction motor. Either A or B. DC shunt motors. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
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