Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. None of these. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. None of these. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generator, armature reaction refers to what? Effect of armature flux on the main field flux. Effect of armature flux on the load. Effect of field flux on the armature flux. None of these Effect of armature flux on the main field flux. Effect of armature flux on the load. Effect of field flux on the armature flux. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has more stability both motors has same stability None of these cylindrical motor salient pole motor both motors has same stability None of these cylindrical motor salient pole motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor will none of these. increase. remains same. Decrease.d none of these. increase. remains same. Decrease.d ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors are used for lathes? Either A or B. Synchronous motor. DC shunt motors. Cage induction motor. Either A or B. Synchronous motor. DC shunt motors. Cage induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor rotates at slip speed with respect to stator mmf. is at standstill with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at the speed of rotor in the air gap. rotates at slip speed with respect to stator mmf. is at standstill with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at the speed of rotor in the air gap. ANSWER DOWNLOAD EXAMIANS APP