Understanding how to approach exam questions helps to boost exam performance. Questions will include short answer, structured, data response and extended response questions.

Do not forget to take a ruler and calculator into the exam.

Maths questions often start with the command words like 'Calculate', 'Determine', 'Estimate' and 'Measure'. They will then include a blank space for you to show your working.

When an answer to a maths question is marked:

- full marks are given for the right answer (but it is wise to show your working so you can check your answer)
- marks are given for working, including substitution and rearrangement
- errors carried forward are taken into account

Errors carried forward are related to what happens if a later answer depends on an earlier answer, and you get the earlier one wrong. You could still get full marks in the later answer if your working is correct but you use the incorrect earlier answer.

If your answer has many decimal places or figures, make sure you give it to an appropriate number of decimal places or significant figures. You may be asked to give units. This may earn you an additional mark, so do not forget to check whether you need to do this.

Some maths questions might ask you to plot or complete a graph or table. When you draw a graph, make sure you:

- plot each point accurately
- draw a best-fit straight line or curve

You may be given a grid with axes and scales already given. Sometimes you may be given an empty grid for you to supply your own axes. When you do this:

- put the independent variable on the x-axis and the dependent variable on the y-axis
- make sensible scales so that the plotted points cover at least 50% of the area of the graph
- label the axes with their quantity and unit, eg time(s)

- Question
The diagram represents a simple electric motor that a pupil investigates in their lesson.

The current in the coil flows from W to Z. This is shown on the diagram.

An ammeter is used to measure the current through the coil.

**a)**Use the diagram to explain how you can determine the direction in which the coil rotates.**[1 mark]****b)**The pupil would like the motor coil to rotate in the opposite direction. Give two different ways that could make this happen.**[1 mark]****c)**The length of YZ is 0.12 m and the magnetic field strength is 5 mT. Select an equation from the list of equations at the start to calculate the reading on the ammeter if the force is 2.4 x 10-^{3}N**[2 marks]**Explain what the effect would be on the coil if the current supplied were doubled and the magnetic field strength halved.

**[2 marks]***Eduqas, GCE Combined Science, SAMs Component 3, 2016 - Higher*.**a) i)**Left hand motor rule [1]Finger of (left hand) represents B-field direction (N to S) and second finger of (left hand) represents current direction (+ to -) [1]

Direction thumb points gives the force direction [1] (coil will rotate clockwise)

**b)**Reverse current [1]Reverse magnetic field [1]

**c)**Manipulation of F = BIL (i.e.) I = F / BL [1]I = 2.4 x 10

^{-3}/ (5 x 10^{-3}x 0.12) = 4 [A] [1]**d)**Current doubles the force but field if half the force [1]Net effect is zero [1]

- Question
The diagram shows a current carrying wire placed in a magnetic field.

**a) i)**What is the usual direction of magnetic field lines between the two poles of a magnet?**[1 mark]****ii)**The wire will experience a force. Use Fleming's left hand rule to predict the direction of this force.**[1 mark]****iii)**Identify two ways this force could be made stronger.**[2 marks]****b) i)**Write down the equation from the list that is used to calculate this force on a current carrying wire in a magnetic field.**[1 mark]****ii)**Use this equation to calculate the magnetic field strength of the above magnet when the wire experiences a force of 0.01 N and a current of 1 A flows. The length of wire in the field is 0.05 m. Give the correct unit for magnetic field strength.**[3 marks]****a) i)**From N to S [1]**ii)**Out of page/screen [1]**iii)**Any**two**from:- stronger magnetic field
- bigger current
- longer wire inside field

[2]

**b) i)**[1]**ii)**[1]So, [1]

[1]