DC Motors Excessive sparking at brushes may be caused due to Loose coupling Worn bearings Dirt on the commutator Misaligment of machine Loose coupling Worn bearings Dirt on the commutator Misaligment of machine ANSWER DOWNLOAD EXAMIANS APP
DC Motors A direct on line starter is used for starting motors Upto 20 HP Upto 5 HP Upto 10 HP Upto 15 HP Upto 20 HP Upto 5 HP Upto 10 HP Upto 15 HP ANSWER DOWNLOAD EXAMIANS APP
DC Motors The mechanical power developed in a dc motor is maximum when back emf is equal to _____ the applied voltage. One-third Twice None of the listed here Half One-third Twice None of the listed here Half ANSWER DOWNLOAD EXAMIANS APP
DC Motors A three point starter is considered suitable for Shunt, compound and series motors Shunt motors Shunt as well as compound motors All D.C. motors Shunt, compound and series motors Shunt motors Shunt as well as compound motors All D.C. motors ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens This will make armature to take heavy current, possibly burning it Motor will come to stop Nothing will happen to motor 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 Motor will come to stop Nothing will happen to motor This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a dc motor is comnected across the AC supply it will Run at normal speed Run at lower speed Burn due to heat produced in the field winding by eddy currents Not run Run at normal speed Run at lower speed Burn due to heat produced in the field winding by eddy currents Not run ANSWER DOWNLOAD EXAMIANS APP