An electric kettle contains water at a temperature of 22∘C22^\circ\text{C}22∘C. The kettle has a power rating of 2.4 kW2.4\text{ kW}2.4 kW and is switched on for 4.0 minutes4.0\text{ minutes}4.0 minutes.
Calculate the energy supplied to the kettle by the electricity supply.
At 4.0 minutes4.0\text{ minutes}4.0 minutes, the temperature of the water reaches 100∘C100^\circ\text{C}100∘C. The volume of the water in the kettle is 1500 cm31500\text{ cm}^31500 cm3 and its density is 1.0 g/cm31.0\text{ g/cm}^31.0 g/cm3. The specific heat capacity of water is 4200 J/(kg∘C)4200\text{ J}/(\text{kg}^\circ\text{C})4200 J/(kg∘C).
Calculate the thermal energy gained by the water.
Calculate the efficiency of the kettle.
119 exam-style questions on CIE IGCSE Physics 2.2.2a Internal energy and temperature. Each one has a worked solution and a mark scheme showing where the marks go.