Maths questions
Maths questions will appear throughout both exams papers (Breadth and Depth), and at both Foundation tier and Higher tier.
Don't forget to take a ruler and a calculator into the exams.
Maths questions often start with the command word 'calculate', followed by a blank space for your working. It is important that you show your working - don't just write the answer down. You might earn marks for your working even if you get the answer wrong.
Always include the correct units for your answer, unless they are already given on the answer line. This may earn you an additional mark.
Check carefully to see if the question tells you to round your answer to a particular number of significant figures or decimal places. And don鈥檛 forget to check your rounding!
If the question does not tell you to round your answer but it has lots of decimal places, you should give your answer to the same number of significant figures as the data in the question. For example, if two significant figures are used in the question, then usually your answer should also be given to two significant figures.
Other command words you might see in maths question include:
- 'predict' (look at some data and suggest an outcome - don't just guess, look at trends in the data and use your scientific knowledge and understanding to make a sensible suggestion)
- 'estimate' (suggest a rough value without doing a calculation - don't just guess, use your scientific knowledge and understanding to make a sensible suggestion)
- 'show' (write down the details, steps or calculations to prove that an answer is correct)
Maths questions might include tables and graphs as well as calculations. When drawing a graph, make sure you:
- put the independent variable (the factor you changed) on the x-axis
- put the dependent variable (the factor you measured) on the y-axis
- construct regular scales for the axes
- label each axis with the quantity and units, eg time (s)
- plot each point accurately
- decide whether the origin (0,0) should be used as a data point
- draw a straight or curved line of best fit if appropriate
Learn maths skills with Dr Alex Lathbridge
Listen to the full series on 大象传媒 Sounds.
Brush up on the maths you need for your exam - percentages, averages and converting units.
Sample question 1 - Foundation
Question
a) A pump is connected to the mains at 230 V and uses a current of 3 A.
Calculate the power of the pump. [3 marks]
b) A charge of 2,160 C flows through a refrigerator. Calculate the time in minutes that the fridge was on for. [4 marks]
Use the equation below in your answer:
charge flow = current 脳 time
OCR 21st Century Science, GCE Physics, Paper J260, 2016.
a) power = current 脳 voltage
230 脳 3 = 690 (W)
When you are not given the equation you need to use in the question, the first thing you should do is write it down. Also check the units - in this case, they are fine so no converting is needed. Put the values into the equation and calculate the answer.
b) 2,160 梅 3 = 720 seconds
Convert 720 seconds into minutes = 720 梅 60 = 12 minutes
In this question the equation is given to you, but the first thing you need to do is to rearrange the equation to give the time.
Place the values for the question into the rearranged equation and this will give you the time in seconds.
Once you've got the answer, you need to convert the answer from seconds into minutes to get the final answer.
Sample question 2 - Higher
Question
Sam is doing an experiment to investigate the output of a solar panel. She is using a small photocell to model the panel.
She is measuring the power output of the photocell when it is different distances from a lamp.
At a distance of 25 cm, the power was 72 mW. The voltage across the photocell was recorded as 12 V. Using the equation:
power = potential difference 脳 current
Calculate the current through the photocell. [4 marks]
OCR 21st Century Science, GCE Physics, Paper J259, 2016 - Higher.
Rearrange the equation to give: current = power 梅 potential difference
Convert mW to W = 0.072 W
= 0.072 梅 12
= 6 x 10-3 A or 6 mA
With all maths questions it is important to look at the units given in the question so as not to make any power of ten errors.
In this question you must rearrange the equation first to give current. Then you must convert mW to watts by dividing by 1,000. Once you have done this, you can put the values into the equation and calculate the answer.
More guides on this topic
- Electric charge - OCR 21st Century
- How to affect electric current - OCR 21st Century
- Series and parallel circuits - OCR 21st Century
- Electrical power and energy - OCR 21st Century
- What are magnetic fields? - OCR 21st Century
- Electric motors - Higher - OCR 21st Century
- What is the process inside an electric generator? - Higher