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 Can be used for 50°C ambient temperature also Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Of lower H.P. should be selected Of higher H.P. should be selected Can be used for 50°C ambient temperature also Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor Of lower H.P. should be selected Of higher H.P. should be selected 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 Runs as a generator Also runs as a motor comes to stop after sometime Does not run as a generator None of these Runs as a generator Also runs as a motor comes to stop after sometime Does not run as a generator ANSWER DOWNLOAD EXAMIANS APP
DC Motors What will happen if the back emf of a dc motor vanishes suddenly? The motor will continue to run The motor will run noisy The motor will stop The armature may burn The motor will continue to run The motor will run noisy The motor will stop The armature may burn ANSWER DOWNLOAD EXAMIANS APP
DC Motors In a D.C. generator, the iron losses mainly take place in Armature conductors Commutator Yoke Armature rotor Armature conductors Commutator Yoke Armature rotor ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens Motor will come to stop This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses This will make armature to take heavy current, possibly burning it Nothing will happen to motor Motor will come to stop This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses This will make armature to take heavy current, possibly burning it Nothing will happen to motor ANSWER DOWNLOAD EXAMIANS APP
DC Motors In D.C. machines the residual magnetism is of the order of 2 to 3 percent 50 to 75 percent 20 to 25 percent 10 to 15 percent 2 to 3 percent 50 to 75 percent 20 to 25 percent 10 to 15 percent ANSWER DOWNLOAD EXAMIANS APP