When three identical bulbs of $60\, W$,$200\, V$ rating are connected in series to a $200\, V$ supply,the power drawn by them will be ................ $W$.

The energy consumed in a $1\, kW$ electric heater in $30$ seconds will be:

The resistance of a device component decreases as the current through it increases and it is described by the relation,$R = \frac{0.2 I}{I-4}$,where $I$ is the current. Determine the minimum power delivered. (Assume $I > 4$) (in $W$)

It takes $12$ minutes to boil $1$ litre of water in an electric kettle. Due to some defect, it becomes necessary to remove $20\%$ of the turns of the heating coil of the kettle. After repair, how much time will it take to boil $1$ litre of water?

For driving a current of $2\, A$ for $6$ minutes in a circuit, $1000\, J$ of work is to be done. The $e.m.f.$ of the source in the circuit is ................ $V$.

How much work is required to carry a $6 \mu C$ charge from the negative terminal to the positive terminal of a $9 V$ battery?