DC Motors If the speed of a dc shunt motor is increased the back emf of the motor will Become zero Increase Decrease Remains same Become zero Increase Decrease Remains same ANSWER DOWNLOAD EXAMIANS APP
DC Motors In variable speed motor None of these Same commutating field is needed at low speed than at high speed A weaker commutating field is needed at low speed than at high speed A stronger commutating field is needed at low speed than at high speed None of these Same commutating field is needed at low speed than at high speed A weaker commutating field is needed at low speed than at high speed A stronger commutating field is needed at low speed than at high speed ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor Of lower H.P. should be selected Of higher H.P. should be selected Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Can be used for 50°C ambient temperature also Of lower H.P. should be selected Of higher H.P. should be selected Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Can be used for 50°C ambient temperature also ANSWER DOWNLOAD EXAMIANS APP
DC Motors The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is 6.77% 8.85% 4.76% 2.22% 6.77% 8.85% 4.76% 2.22% ANSWER DOWNLOAD EXAMIANS APP
DC Motors One D.C. motor drives another D.C. motor. The second D.C. motor when excited and driven None of these Also runs as a motor comes to stop after sometime Runs as a generator Does not run as a generator None of these Also runs as a motor comes to stop after sometime Runs as a generator Does not run as a generator ANSWER DOWNLOAD EXAMIANS APP
DC Motors The main disadvantage of the Ward-Leonard control method is High initial cost High maintenance cost Low efficiency at high loads All of these High initial cost High maintenance cost Low efficiency at high loads All of these ANSWER DOWNLOAD EXAMIANS APP
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