In a home experiment, Ram brings a new electric (heat capacity = ) kettle with…

PHYSICS · Single correct · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter

Problem

In a home experiment, Ram brings a new electric (heat capacity =

4200\,\text{J}/^{\circ}\text{C}

) kettle with unknown power rating. He puts

1\,\text{litre}

water in the kettle and switches on. But to his dismay, the temperature becomes constant at

60^{\circ}\text{C}

after some time. The room temperature is

20^{\circ}\text{C}

. Ram gets bored and switches off the kettle. He sees that during first

20\,\text{s}

water cools down by

2^{\circ}\text{C}

. What is the wattage of the kettle? (A) 840W (B) 1W (C) 100W (D) 420 W