Physics GCSE Key Questions and Answers

Cooling:

How is heat (thermal energy) transferred and what factors affect the rate at which heat is transferred?

To evaluate ways in which heat is transferred in and out of bodies and ways in which the rates of these transfers can be reduced.

How to carry out an investigation concerning the effect that insulation has on the rate of loss of heat from a container.

1. Put insulation around a beaker. 
2. The beaker can then be filled with hot water. 
3. Cover the top of the beaker with a cardboard lid, with a hole in the lid for a thermometer to be put through.
4. Measure the initial temperature of the water and the temperature after a suitable time in order to determine the temperature drop. 
5. For a fair experiment investigate changing either the type of insulation or the thickness of the insulation. 
6. It is not necessary for each person to carry out a large number of such investigations, as the results of the class may be pooled. However, if class results are to be pooled, it is essential that different groups must have conducted the experiment in the same way.

Resistance:

What does the current through an electrical circuit depend on?

The resistance of a component can be found by measuring the current through and potential difference across the component.

What are the steps to carry out an investigation concerning how the length of a wire affects the resistance.

1. Use a length of 36 SWG constantan wire. 
2. Measure the resistance directly by using a multimeter set to resistance or use an ammeter in series and a voltmeter in parallel and then calculate the resistance.
3. Pay attention to the fact that when the current is too high the wire can get very hot, especially if one decides to use short lengths of wire.