Winding conductors of an electrical power transformer are mainly insulated by paper insulation. wooden insulation. cotton insulation. rubber insulation. TRUE ANSWER : ? YOUR ANSWER : ?
The armature voltage control is considered suitable for a DC motor driven at constant torque. speed. power. current. TRUE ANSWER : ? YOUR ANSWER : ?
The basic function of a transformer is to change the level of the voltage the power level the power factor the frequency TRUE ANSWER : ? YOUR ANSWER : ?
For a given torque, reducing diverter resistance of a DC series motor causes increase in speed but armature currnet remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. decrease in speed but armature current remains the same. TRUE ANSWER : ? YOUR ANSWER : ?
A part an alternator winding consist of eight coils in series, each having an emf of 20 V rms induced in it. Coils are placed in successive slots and between each slot and the next, there is an electrical phase displacement of 30°. Find the emf of eight coils in series 86.91 V. 76.91 V. 66.91 V. 56.91 V. TRUE ANSWER : ? YOUR ANSWER : ?
Regenerative braking is not found in which motor? DC series. DC compound. Induction motor. DC shunt. TRUE ANSWER : ? YOUR ANSWER : ?
In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve starting torque. reduce copper loss. improve power factor. improve efficiency. TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is/are the methods to reduce the armature reaction and its effects? pole stacking All of these pole chamfering compensating winding TRUE ANSWER : ? YOUR ANSWER : ?
In which of the following, voltage regulation may be zero or negative lagging power factor leading power factor unity power factor All of these TRUE ANSWER : ? YOUR ANSWER : ?
A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is some what more than 230 V 230 V some what less than 230 V not possible TRUE ANSWER : ? YOUR ANSWER : ?