In a synchronous generator with constant steam input supplies power to an infinite bus at a lagging power factor. If the excitation is increased power angle decrease and power factor increase both power angle and power factor decrease both power angle and power factor increase power angle increase and power factor decrease TRUE ANSWER : ? YOUR ANSWER : ?
If a DC motor is connected across the AC supply it will Not run. Run at lower speed. Burn. Run at normal speed. TRUE ANSWER : ? YOUR ANSWER : ?
The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are 2, 3, 4, 5 1, 3, 4, 5 2, 3, 4 1, 2, 3, 4 and 5 TRUE ANSWER : ? YOUR ANSWER : ?
DC Shunt Motor has disadvantage(s) of less expensive. none of above. not suitable for rapidly changing loads. constant speed. TRUE ANSWER : ? YOUR ANSWER : ?
Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. TRUE ANSWER : ? YOUR ANSWER : ?
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. 280 V. 150 V. 220 V. 240 V. TRUE ANSWER : ? YOUR ANSWER : ?
Star - delta method of starting of motor is not possible in case of low horse power motor. high speed motor. single phase induction motor. high torque motor. TRUE ANSWER : ? YOUR ANSWER : ?
The overall power factor of an on load transformer is always unity. depends on the power factor of the load. is always leading. is always lagging. TRUE ANSWER : ? YOUR ANSWER : ?
Transformers operating in parallel will share the load depending upon their percentage impedance. rating. leakage reactance. efficiency. TRUE ANSWER : ? YOUR ANSWER : ?
A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net voltage across the armature resistance at the time of plugging will be 6 V 240 V 474 V 234 V TRUE ANSWER : ? YOUR ANSWER : ?