81. What will happen if we increase the air gap in the induction motor?
A. Power factor will reduce
B. Power factor will increase
C. Reduction in harmonics
D. Speed will increase
82. The ratio of the rotor copper loss and air gap power is _______
83. Magnetizing current in the induction motor is ______
A. more than the transformer
B. equal as a transformer
C. less than the transformer
84. Single phase induction motor is self-starting.
85. What is the speed of the 6th order time harmonics in the induction motor?
86. What is the speed of the 11th-order harmonics in the induction motor?
87. A 3 – phase, 4-pole IM is supplied from a 40 Hz source. Calculate rotor frequency when the rotor runs 100 rpm.
A. 35 Hz
B. 36.6 Hz
C. 9 Hz
D. 8 Hz
88. Calculate the three-phase power using the following data: Vp=23 V,
Ip=23 A, ∅=60.
A. 793.5 W
B. 790 W
C. 792 W
D. 791 W
89. What is the condition for the maximum power transfer theorem in DC circuits?
C. RL≫ Rth
90. Instantaneous power in the 3-φ system is constant.