Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will develop excessive speed and damage itself. open fuse or circuit breaker. produce sparking at brushes. draw too much current. develop excessive speed and damage itself. open fuse or circuit breaker. produce sparking at brushes. draw too much current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, 1. physically, the brush axis is along the direct axis 2. physically, the brush axis is along the interpolar axis 3. schematically, the brush axis is along the direct axis 4. schematically, the brush axis is along the quadrature axis 5. armaturemmf is directed along the brush axis From these, the correct statements are 1, 4,5 2, 4, 5 1 , 3, 5 2, 3, 5 1, 4,5 2, 4, 5 1 , 3, 5 2, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cross magnetization effects which of the following? reduces the terminal voltage both 2 and 3 commutation reduction in main field flux reduces the terminal voltage both 2 and 3 commutation reduction in main field flux ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a single phase transformer the magnitude of leakage reactance is twice that of resistance of both primary and secondary. With secondary short circuited, the input power factor is 1/3 1/√5 1/√2 2/√5 1/3 1/√5 1/√2 2/√5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc motor with armature resistance of 0.5 ohms connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 570 A. 250 A. 340 A. 460 A. 570 A. 250 A. 340 A. 460 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is same. more. between 50% and 90%. less than 50%. same. more. between 50% and 90%. less than 50%. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS