DC Motors In a dc machines the residual magnetism is of the order of 50 to 75 percent 2 to 3 percent 10 to 15 percent 20 to 25 percent 50 to 75 percent 2 to 3 percent 10 to 15 percent 20 to 25 percent ANSWER DOWNLOAD EXAMIANS APP
DC Motors The rheostatic speed control method is very Unsuitable for rapidly changing loads Efficient Suitable for getting speeds above the normal Economical Unsuitable for rapidly changing loads Efficient Suitable for getting speeds above the normal Economical ANSWER DOWNLOAD EXAMIANS APP
DC Motors The iron loss in dc motor depends on Both flux and speed None of the listed here Flux only Speed only Both flux and speed None of the listed here Flux only Speed only ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens This will make armature to take heavy current, possibly burning it Nothing will happen to the motor This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses Motor will run at very slow speed This will make armature to take heavy current, possibly burning it Nothing will happen to the motor This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses Motor will run at very slow speed ANSWER DOWNLOAD EXAMIANS APP
DC Motors The starting resistance of a DC motor is generally Infinitely large Low 1000 Ω Around 500 Ω Infinitely large Low 1000 Ω Around 500 Ω ANSWER DOWNLOAD EXAMIANS APP
DC Motors Excessive sparking at brushes may be caused due to Loose coupling Misaligment of machine Dirt on the commutator Worn bearings Loose coupling Misaligment of machine Dirt on the commutator Worn bearings ANSWER DOWNLOAD EXAMIANS APP