SSC JE Electrical Engineering 2011

The power input to a 3-phase, 50 Hz, 400 V, 4-pole induction motor is 60 kW and its stator losses are 1 kW. If this motor is running at 4% slip, the rotor copper loss is

In a transformer, the core loss is found to be 46 W at 50 Hz and is 80 W at 70 Hz, both losses being measured at the same peak flux density. The hysteres is loss and eddy current loss at 60 Hz is

The voltage wave given by $$v = 4 \cos \omega t$$ produces a current wave $$i = 1.5 \cos \omega t - 2.598 \sin \omega t$$ in a circuit. The current wave

The damping is D Arsonval galvanometer is obtained by

If $$\theta$$ represents deflection of pointer, the controlling torque in a spring-controlled indicating instrument is proportional to

The range of a DC milliammeter can be extended by using a

For use in AC circuits, potential coil circuit of electrodynamic wattmeter should be purely

A DC shunt generator builds upto 230 V. Other conditions remaining same, if only the residual magnetism of the original machine is reversed, the voltage to which the generator will build up is

A 100 kVA single phase transformer exhibits maximum efficiency at 80% of full load and the total loss in the transform under this condition is 1000 W. The ohmic losses at full load will be

If a 3-phase induction motor hums during starting up, the probable cause could be