Electrical Machines If the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then Pe will increase but Ph will decrease Ph will decrease but Pe will remain same Ph will increase but Pe will decrease both hysteresis loss(Ph) and eddy current loss(Pe) will increase Pe will increase but Ph will decrease Ph will decrease but Pe will remain same Ph will increase but Pe will decrease both hysteresis loss(Ph) and eddy current loss(Pe) will increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous machine has P number of poles, find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm)? ωe = P*ωm ωe = ωm ωe = 2/P*ωm ωe = P/2*ωm ωe = P*ωm ωe = ωm ωe = 2/P*ωm ωe = P/2*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an induction motor, what is the ratio of rotor input to rotor copper loss? 1/S 1-S 1/(1-S) S 1/S 1-S 1/(1-S) S ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies directly as synchronous reactances Xs All of these inversely as 1/Xs directly as Xs2 directly as synchronous reactances Xs All of these inversely as 1/Xs directly as Xs2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting phenomenon is observed in which motor? DC motor. Induction motor. Both A and C. Synchronous motor. DC motor. Induction motor. Both A and C. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf of a DC machine has triangular space distribution and is stationary in space. trapezoidal space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. trapezoidal space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. stepped distribution and rotates at the speed of armature. ANSWER DOWNLOAD EXAMIANS APP