DC Motors The rheostatic speed control method is very Economical Unsuitable for rapidly changing loads Suitable for getting speeds above the normal Efficient Economical Unsuitable for rapidly changing loads Suitable for getting speeds above the normal Efficient ANSWER DOWNLOAD EXAMIANS APP
DC Motors Which method of braking is generally used in elevators? Regenerative braking Plugging None of these Rheostat braking Regenerative braking Plugging None of these Rheostat braking ANSWER DOWNLOAD EXAMIANS APP
DC Motors The back emf in a dc motor ______ None of the listed here Aids the armature current Opposes the applied voltage Aids the applied voltage None of the listed here Aids the armature current Opposes the applied voltage Aids the applied voltage ANSWER DOWNLOAD EXAMIANS APP
DC Motors The main disadvantage of the Ward-Leonard control method is All of these High maintenance cost Low efficiency at high loads High initial cost All of these High maintenance cost Low efficiency at high loads High initial cost ANSWER DOWNLOAD EXAMIANS APP
DC Motors If conditions for maximum power for a dc motor are established, the efficiency of the motor will be 60 to 70 % 80 to 90 % Less than 50% 100 % 60 to 70 % 80 to 90 % Less than 50% 100 % ANSWER DOWNLOAD EXAMIANS APP
DC Motors In variable speed motor A stronger commutating field is needed at low speed than at high speed None of these A weaker commutating field is needed at low speed than at high speed Same 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 A weaker commutating field is needed at low speed than at high speed Same commutating field is needed at low speed than at high speed ANSWER DOWNLOAD EXAMIANS APP
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