The heat produced by a $100\, W$ heater in $2\, minutes$ will be equal to:

The maximum current that flows through a fuse wire before it blows out varies with its radius as

Two wires have resistances of $2 \ \Omega$ and $4 \ \Omega$ and are connected to the same voltage. The ratio of heat dissipated in the resistances is:

According to Joule's law,if the potential difference across a conductor having a material of specific resistance remains constant,then the heat produced in the conductor is directly proportional to

The maximum power drawn from a source with electromotive force $E$ and internal resistance $r$ is given by:

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?