Question

The radiator of a car contains $20L$ water. If the motor supplies $2\times {10}^{5}cal$ heat to it, then rise in its temperature will be

• A. ${1000}^{o}C$
• B. ${100}^{o}C$
• C. ${20}^{o}C$
• D. ${10}^{o}C$

Answer 1

The correct option is D ${10}^{o}C$

20 litre of water has a mass of 20 kg.($\rho =1000kg/m^3$). Heat is given as $2\times {10}^{5}cal=200kcal$
Using the relation $Q=mc\Delta T$ we have $200=20\times 1\times \Delta T$.Thus we get $\Delta T={10}^{o}C$