An immersion heater of resistance is used to warm of water initially at

PHYSICS · Multi-part · CBSE · Physics · Current Electricity · Current Electricity

Problem

An immersion heater of resistance

20\,\Omega

is used to warm

1.5\,\text{kg}

of water initially at

25^{\circ}\text{C}

. The heater is connected to a

220\,\text{V}

supply and is switched on for

10\,\text{min}

. Ignoring any heat losses to the surroundings and taking the specific heat capacity of water to be

4.2\times10^{3}\,\text{J kg}^{-1}\!{}^{\circ}\text{C}^{-1}

, answer the following: (i) Calculate the electrical energy supplied by the heater in the

10\,\text{min}

period. (ii) Determine the rise in temperature of the water produced in this time.