Two dc machines A and B, using the same conductor material, have armature circuit resistances of 0.4 Ω and 1.2 Ω respectively. Of the two machines, A is bigger than B for the same current rating B is bigger than A for the same current rating both are of the same size for the same current rating A is bigger than B for the same voltage rating TRUE ANSWER : ? YOUR ANSWER : ?
In a resistance split phase motor, what is the range of torque angle? 0° 25° to 30° 90° 70° to 85° TRUE ANSWER : ? YOUR ANSWER : ?
The field divertor resistance for a DC series motor is of order of 0.1 Ω 100 Ω 10 Ω 50 Ω TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following pairs is/are correct? open slot----- leakage flux is less semi closed slot-----leakage flux is moderate closed slot----- leakage flux is high All of these TRUE ANSWER : ? YOUR ANSWER : ?
The principle of operation of a 3 - Φ induction motor is almost similar to that of transformer with secondary short circuited. capacitor start induction motor. synchronous motor. repulsion start induction motor. TRUE ANSWER : ? YOUR ANSWER : ?
In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side leads by 30°. Star side leads by 30°. Delta side lags by -30°. Star side lags by -30°. TRUE ANSWER : ? YOUR ANSWER : ?
The constant losses in transformer is/are copper loss. hysteresis loss. both 2 and 3. eddy current loss. TRUE ANSWER : ? YOUR ANSWER : ?
A 3 - Φ slip ring motor has wound rotor. any of the above. short-circuited rotor. double cage rotor. TRUE ANSWER : ? YOUR ANSWER : ?
Maximum efficiency will occur, when copper loss is_______to iron loss? equal to less than greater than any of the above TRUE ANSWER : ? YOUR ANSWER : ?
In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will deteriorate with fall of terminal voltage. improve with fall of terminal voltage. improve with rise in terminal voltage. deteriorate with rise in terminal voltage. TRUE ANSWER : ? YOUR ANSWER : ?