Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by sf / 2. s2. f / s. sf. sf / 2. s2. f / s. sf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will decrease. remain unaltered. become execessively high. increase. decrease. remain unaltered. become execessively high. increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.2 lag 0.2 lead 0.9 lag unity 0.2 lag 0.2 lead 0.9 lag unity ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing inter poles. compensating winding. any one or more of the above methods. high resistance carbon brushes. inter poles. compensating winding. any one or more of the above methods. high resistance carbon brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 2 .1 Ω 1.79 Ω 3.1 Ω 1.8 9 Ω 2 .1 Ω 1.79 Ω 3.1 Ω 1.8 9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms connected directly to a 220 Volt supply. If the armature is stationary then the current flowing through the armature is 440 A. 250 A. 570 A. 340 A. 440 A. 250 A. 570 A. 340 A. ANSWER DOWNLOAD EXAMIANS APP
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