when three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is

The magnetic flux through a circuit of resistance R changes by an amount $$\Delta $$$$\phi $$ in a time $$\Delta $$t. Then the total quantity of electric charge Q that passes any point in the circuit during the time $$\Delta $$t is represented by

The refractive index of the material of a prism is $$\sqrt 2 $$ and its refracting angle is 30^o. One of the refracting surfaces of the prism is made a mirror inwards. A beam of monochromatic light entering the prism from the other face with retrace its path after reflection from the mirrored surface if its angle of incidence on the prism is