Electrical Machines A 4 pole, 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 720 rpm, the supply frequency is 50 Hz 60 Hz 40 HZ 25 Hz 50 Hz 60 Hz 40 HZ 25 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will reduce by 5 %. depend on other factors. remain unchanged. increase by 5 %. reduce by 5 %. depend on other factors. remain unchanged. increase by 5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine torque depends on which of the following? flux (φ) armature current (I) speed both A and B flux (φ) armature current (I) speed both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = sX2. sR2 = X2. R2 = s2X2. R2 = s2X2. R2 = sX2. sR2 = X2. R2 = s2X2. R2 = s2X2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will draw too much current. produce sparking at brushes. develop excessive speed and damage itself. open fuse or circuit breaker. draw too much current. produce sparking at brushes. develop excessive speed and damage itself. open fuse or circuit breaker. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Lamination of core are generally made of silicon steel. cast iron. stainless steel. carbon. silicon steel. cast iron. stainless steel. carbon. ANSWER DOWNLOAD EXAMIANS APP
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