Electrical Machines For 250 volt DC Shunt Motor the armature and field resistance are 0.5 ohm and 250 ohm respectively. What will be the back e.m.f. produced when it takes a load current of 21A. 150 V. 280 V. 240 V. 220 V. 150 V. 280 V. 240 V. 220 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines There are two 2-pole DC machines. Main field axis of machine A is horizontal and that of B is vertical. It is preferable to purchase machine B any of the two machines machine A none of these machine B any of the two machines machine A none of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is the largest conversion device? Synchronous machine Induction machine DC machine All of these Synchronous machine Induction machine DC machine All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward Leonard control is provides speed control Above rated speed. In both direction. Below rated speed. In one direction only. Above rated speed. In both direction. Below rated speed. In one direction only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3-phase induction motor, if the supply voltage and frequency are reduced by the same ratio, then slip at which maximum torque occurs is more and maximum torque decreases less and maximum torque decreases more and maximum torque remains constant less and maximum torque increases more and maximum torque decreases less and maximum torque decreases more and maximum torque remains constant less and maximum torque increases 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, 2 and 3 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
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