Two of supply terminals to a 3 - Φ induction motor get interchanged during re-connection after normal maintenance. When switched on the supply, the motor will rotate in direction opposite to that before maintenance. not start at all. rotate in the same direction as before maintenance. get heated and damaged. TRUE ANSWER : ? YOUR ANSWER : ?
The speed of a 3-phase induction motor operating in its stable region remains constant. decreases with decrease in the load torque. decreases with increase in the load torque. increases with increase in the load torque. TRUE ANSWER : ? YOUR ANSWER : ?
In a DC Motor 3 point starter is used to all of above. limit the starting current to a safer value. provide overload protection. provide protection against Low-Voltage. TRUE ANSWER : ? YOUR ANSWER : ?
Compensating winding are used to rectify the flux density waveform at throughout the air gap. None of these interpole region. region under main pole. TRUE ANSWER : ? YOUR ANSWER : ?
In travelling cranes for crane travel, trolley and boom hoist which motor is preferred? Slip ring induction motor. Stepper motor. DC differential compound motor. Synchronous motor. TRUE ANSWER : ? YOUR ANSWER : ?
The inertia constant H of a synchronous condenser is equal to that of the effective length of the line. greater than that of hydro generator. greater than that of turbo alternator. none of these. TRUE ANSWER : ? YOUR ANSWER : ?
For which of the following loads, armature reaction is magnetizing in nature? None of these pure capacitive load pure resistive load pure inductive load TRUE ANSWER : ? YOUR ANSWER : ?
In a DC generator if field winding attains the critical resistance machine will generate maximum voltage. field winding will burn. machine will generate maximum power. the voltage generated will be zero. TRUE ANSWER : ? YOUR ANSWER : ?
In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. mechanical rotatory system. restoring torque. damping torque. synchronizing power co efficient. TRUE ANSWER : ? YOUR ANSWER : ?
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 A machine B none of these any of the two machines TRUE ANSWER : ? YOUR ANSWER : ?