Electrical Machines Which of the following methods are used to control the speed of DC motors is field current control armature circuit resistance control All of these supply voltage control field current control armature circuit resistance control All of these supply voltage control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is suitable for frequent starting and stoppings? All of these Capacitor start motor Capacitor start capacitor run motor Resistance split phase motor All of these Capacitor start motor Capacitor start capacitor run motor Resistance split phase motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the shunt resistance component equivalent circuit obtained by no load test of an induction motor representative of ? windage and friction loss both 1 and 2 Copper loss core loss only windage and friction loss both 1 and 2 Copper loss core loss only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 72.5% 82.5% 67.5% 78.5% 72.5% 82.5% 67.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft torque of a dc motor is less than the electromagnetic torque because of hysteresis losses. mechanical losses. ohmic losses. eddy current losses. hysteresis losses. mechanical losses. ohmic losses. eddy current losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which machine is used for battery charging? None of these. DC series generator. Compounded DC generator. DC shunt generator. None of these. DC series generator. Compounded DC generator. DC shunt generator. ANSWER DOWNLOAD EXAMIANS APP
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