Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 10% increased by 10% increased by 20% reduced by 20% reduced by 10% increased by 10% increased by 20% reduced by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a fault at the terminal of a synchronous generator, the fault current is maximum for a 3 - phase fault. 3 - phase to ground fault. line to ground fault. line to line fault. 3 - phase fault. 3 - phase to ground fault. line to ground fault. line to line fault. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor when started on no load does not accelerate up to full speed but runs at 1/7th of the rated speed. The motor is said to be plugging. cogging. locking. crawling. plugging. cogging. locking. crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of permanent magnets. None of these residual magnetism. armature reaction. permanent magnets. None of these residual magnetism. armature reaction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be equal to number of rotor slots. an integral multiple of number of rotor slots. unequal to number of rotor slots and skewed in shape. either (B) or (C). equal to number of rotor slots. an integral multiple of number of rotor slots. unequal to number of rotor slots and skewed in shape. either (B) or (C). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dc motor with armature winding resistance of 0.6 ohm receives a supply of 230 Volt. If the back emf produced during running condition is equal to 210 volt. Calculate the current flowing through the armature at this point. 43 Amp. 33.33 Amp. 44.47 Amp. 29 Amp. 43 Amp. 33.33 Amp. 44.47 Amp. 29 Amp. ANSWER DOWNLOAD EXAMIANS APP