IGCSE Physics Quiz: Thermal Physics

(a) The source of solar energy is the Sun. Tick the box next to those resources for which the Sun is also the source of energy. coal geothermal hydroelectric nuclear wind [2]

• coal

• geothermal

• hydroelectric

• nuclear

• wind

(i)Explain why the tubes are made of copper and are painted black.

(ii)In 5.0 s, 0.019 kg of water flows through the tubes. The temperature of the water increases from 20 °C to 72 °C. The specific heat capacity of water is 4200 J / (kg °C). Calculate the thermal energy gained by the water in 5.0 s.

(iii)The efficiency of the solar panel is 70%. Calculate the power of the solar radiation incident on the panel.

(a) State what is meant by the specific heat capacity of a substance.

(b)A student carries out an experiment to find the specific heat capacity of aluminium. He uses an electric heater and a thermometer, inserted into separate holes in an aluminium block. The following data are obtained. mass of aluminium block = 2.0 kg power of heating element = 420 W time of heating = 95s initial temperature of block = 19.5 °C final temperature of block = 40.5 °C Calculate the value of the specific heat capacity of aluminium given by this experiment.

(c)In the experiment in (b), no attempt is made to prevent loss of thermal energy from the surfaces of the block. Suggest two actions the student could take to reduce the loss of thermal energy from the surfaces of the block.

(a) Fig. 4.1 shows a device used as a thermocouple thermometer. In the table put three ticks against the correct statements about the thermocouple thermometer. Meter Z measures energy. Meter Z measures potential difference. Meter Z measures power. Materials X and Y are different materials. Materials X and Y are the same material. Materials X and Y are electrical conductors. Materials X and Y are electrical insulators.

• Meter Z measures power.

• Meter Z measures energy.

• Materials X and Y are electrical conductors.

• Materials X and Y are different materials.

• Meter Z measures potential difference.

(b)A liquid-in-glass thermometer is replaced by a similar thermometer with a larger bulb. No other change is made. State and explain the effect on the sensitivity.

(c)The capillary of a liquid-in-glass thermometer should have a constant diameter. Fig. 4.2 shows the capillary of a thermometer made with a manufacturing fault. State and explain the effect of this fault on the linearity of the thermometer.