DC Motors In variable speed motor None of these 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 A weaker 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 stronger commutating field is needed at low speed than at high speed A weaker commutating field is needed at low speed than at high speed ANSWER DOWNLOAD EXAMIANS APP
DC Motors The starting resistance of a DC motor is generally 1000 Ω Low Infinitely large Around 500 Ω 1000 Ω Low Infinitely large Around 500 Ω ANSWER DOWNLOAD EXAMIANS APP
DC Motors In case the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be Less than 50% 1 Around 90% Anywhere between 75% and 90% Less than 50% 1 Around 90% Anywhere between 75% and 90% ANSWER DOWNLOAD EXAMIANS APP
DC Motors A dc series motor is best suited for driving Cranes and hoists Machine tools Shear and punches None of the listed here Cranes and hoists Machine tools Shear and punches None of the listed here ANSWER DOWNLOAD EXAMIANS APP
DC Motors When the armature of a D.C. motor rotates, e.m.f. induced is Mutually induced e.m.f. Self-induced e.m.f. Back e.m.f. None of these Mutually induced e.m.f. Self-induced e.m.f. Back e.m.f. None of these 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 Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Of higher H.P. should be selected Can be used for 50°C ambient temperature also Of lower H.P. should be selected Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Of higher H.P. should be selected Can be used for 50°C ambient temperature also ANSWER DOWNLOAD EXAMIANS APP