Which DC motor will have least percentage increase of input current, for the same percentage increase in the torque DC Series Motor DC Shunt Motor Separately Excited DC Motor Compound Wound DC Motor TRUE ANSWER : ? YOUR ANSWER : ?
A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.649. 0.512. 0.573. 0.443. TRUE ANSWER : ? YOUR ANSWER : ?
Compensating windings are used in DC generators to neutralize the cross magnetizing effect of the armature reaction. to provide path for the circulation of cooling air. None of these mainly to reduce the eddy currents by providing local short circuit. TRUE ANSWER : ? YOUR ANSWER : ?
On which of the following factor/factors the speed of a DC motor depends upon? Armature current. Field flux. All of these. Applied voltage. TRUE ANSWER : ? YOUR ANSWER : ?
In above question, find rms line voltage for delta connection? 50 V. 399 V. 100 V. 230.2 V. TRUE ANSWER : ? YOUR ANSWER : ?
The starting resistance of DC motor is generally Low. 1000 ohms. Infinitely large. around 500 ohms. TRUE ANSWER : ? YOUR ANSWER : ?
In DC generator, full form of MNA is what? Magnetic neutral armature co-ordinate. Magnetic no-load axis. Magnetic neutral axis. Magnetically no-load armature co-ordinate. TRUE ANSWER : ? YOUR ANSWER : ?
Number of slip rings in 3-phase synchronous motor will be 1 3 or 4 2 0 TRUE ANSWER : ? YOUR ANSWER : ?
Where the shunt generators are widely used? Where often load fluctuation is occurred. Where voltage variation is needed over a wide load range. Where a constant voltage is required over a narrow load range. Where the load is very high. TRUE ANSWER : ? YOUR ANSWER : ?
An auto transformer having a transformation ratio of 0.8 supplies a load pf 10 KW. The power transfered inductively from the primary to secondary is 8 KW. 0. 2 KW. 10 KW. TRUE ANSWER : ? YOUR ANSWER : ?