One to two mark questions will start with command words such as 'describe' or 'explain'. Some command words are easy to understand such as:
The command words 'describe' and 'explain' can be confusing. If you are asked to describe a graph, you will be expected to write about its overall shape, whether it is linear or curved, the slope of gradients etc. If you are asked to explain why a pattern or trend is seen in a graph, you will be expected to use your science knowledge, not just say what you see (which is a description), eg 'The graph shows a steep linear increase for the first three hours because…'.
'Explain how' and 'why' questions often have the word 'because' in their answer. 'Describe' questions don't.
The number of marks per question part is given in this form: '[2 marks]'. It is essential that you give two different answers if a question is worth two marks. Sometimes you can gain a second mark by giving the units in a calculation or stating specific data points, eg the speed of the object decreased by 8 m/s.
Edexcel questions courtesy of Pearson Education Ltd.
Transformers are designed to use alternating current. Describe what change happens when a step-up transformer is used. [2 marks]
The voltage increases.
The figures below show different voltages that can be applied across a wire.
Explain which of the voltages in the figures causes an ac current in the wire. [2 marks]
Alternating current changes direction which means that on the graph it will have a negative voltage followed by a positive voltage or vice versa. Of the two figures, Figure 1 shows negative voltage and positive voltage, so it is the one that causes an ac current in the wire.
The table shows some electrical components.
Put ticks in the table next to the two components the generator must contain. [2 marks]
|Coil of wire|
|Coil of wire||✔|
A generator is connected to a lamp. The current in the lamp is alternating causing the bulb to light up. The generator is turned faster.
Explain what happens to the lamp. [2 marks]
The bulb is brighter because the voltage produced by the generator is higher.