Electrical Machines For a 3-phase, 4 pole, 50 Hz synchronous motor the frequency, pole number and the frequency are halved. The motor speed will be 3000 rpm 75 rpm 375 rpm 1500 rpm 3000 rpm 75 rpm 375 rpm 1500 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine is in the same direction as the main poles. makes an angle with the main pole axis which is load dependent. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. is in the same direction as the main poles. makes an angle with the main pole axis which is load dependent. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings is placed in which part of a D.C motor? On yoke in the inter pole gap. None of these On yoke in the pole faces. On armature. On yoke in the inter pole gap. None of these On yoke in the pole faces. On armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature reaction mmf in a DC machines has a form of rectangular. sinusoidal. trapezoidal. triangular. rectangular. sinusoidal. trapezoidal. triangular. ANSWER DOWNLOAD EXAMIANS APP
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 increased by 20% reduced by 10% reduced by 20% increased by 10% increased by 20% reduced by 10% reduced by 20% increased by 10% ANSWER DOWNLOAD EXAMIANS APP