Electrical Machines An induction motor has synchronous speed of 1500 rpm. What will be the slip when it is running at a speed of 1450 rpm? +3.33% -3% +3% -3.33% +3.33% -3% +3% -3.33% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-winding single-phase motor has high starting torque. starting torque equal to full-load torque. zero starting torque. low starting torque. high starting torque. starting torque equal to full-load torque. zero starting torque. low starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The teeth in the armature of a DC machines are sometimes skewed. This is done to reduce copper loss. eddy electric current loss. vibrations. hysteresis loss. copper loss. eddy electric current loss. vibrations. hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf of a DC machine has stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 8Ω and Xq = 10.8Ω ANSWER DOWNLOAD EXAMIANS APP