Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 5% 19% 40% 10% 5% 19% 40% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be either (B) or (C). an integral multiple of number of rotor slots. equal to number of rotor slots. unequal to number of rotor slots and skewed in shape. either (B) or (C). an integral multiple of number of rotor slots. equal to number of rotor slots. unequal to number of rotor slots and skewed in shape. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Motor is driving a constant load torque having armature resistance of 0.25 Ω and armature current of 60 A having connected to a voltage of 230 V. Now a resistance of 1 ohm is added into the armature circuit. The ratio of their speed will be 0.25. 0.62. 0.72. 1.24. 0.25. 0.62. 0.72. 1.24. 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 3.1 Ω 1.8 9 Ω 1.79 Ω 2 .1 Ω 3.1 Ω 1.8 9 Ω 1.79 Ω 2 .1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motors has low ratings only? Resistance split phase Capacitor start Capacitor run Shaded pole Resistance split phase Capacitor start Capacitor run Shaded pole ANSWER DOWNLOAD EXAMIANS APP
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