A student carries out an experiment to determine the thermal capacity of a metal block. The block is heated by an electric heater for 18 minutes18\text{ minutes}18 minutes. The current in the heater is 4.5 A4.5\text{ A}4.5 A at a potential difference (p.d.) of 15 V15\text{ V}15 V. The temperature of the block rises from 22∘C22^\circ\text{C}22∘C to 82∘C82^\circ\text{C}82∘C.
Calculate the thermal capacity of the block.
Two metal spheres of different diameters are heated to 800∘C800^\circ\text{C}800∘C in an oven. The two spheres are removed from the oven.
State and explain any difference in the initial rates of emission of radiation of thermal energy between the two spheres.
One hot sphere is now heated in a hotter oven.
State and explain any effect on the rate of emission of radiation of thermal energy from that sphere when it is removed from the hotter oven.
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.