Electricity - Six-mark questions

Six-mark questions are extended open response questions. These require longer answers than the structured questions with fewer marks. It is wise to plan your answer rather than rushing straight into it, otherwise you may stray away from the key points.

Six-mark questions are marked using a levels-based mark scheme because they are open ended. To gain full marks, you need to:

  • support explanations using scientific knowledge and understanding
  • use appropriate scientific words and terms
  • write clearly, linking ideas in a logical way
  • maintain a sustained line of reasoning, rather than getting lost or bogged down

You are likely to see command words such as:

  • 'describe' - you need to give an account but no reason
  • 'explain' - you must give reasons or explanations
  • 'devise' - you must plan or invent a procedure using your scientific knowledge and understanding
  • 'evaluate' - you must review information, including identifying strengths and weaknesses, and make a supported conclusion

Six-mark questions may be synoptic questions. These questions bring together ideas from two or more topics. For example, a question about atoms could include ideas about atomic structure, isotopes, radiation and nuclear reactions. Remember that the topics covered in the first paper are assumed knowledge for the second paper, so questions in the second paper may need knowledge and understanding of those topics too.

The answers shown here give marking points as bullet points. You do not usually need to include all of them to gain six marks, but you do need to write in full sentences, linking them logically and clearly.

Sample question 1 - Foundation


A holidaymaker wished to visit the USA for a fortnight. The voltage of the mains electricity in the UK is 230 V. In the USA. the voltage is 110 V. A hair dryer has information on it stating 1,500 W, 230 V. It is intended for use in the UK. Explain what difference the holiday maker would experience in the use of the hairdryer in the USA. Also explain the advantages and disadvantages of having mains voltage at 110 V. [6 marks]

This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.


I  =  \frac{P}{V}

=  \frac{1,500}{230} =  6.52~A [1]

R  =  \frac{V}{I}

=  \frac{230}{6.52} = 35.3~\Omega [1]


I  =  \frac{V}{R}

=  \frac{110}{35.3} =  3.11~A [1]

P  =  I^2 R

=  3.11^2  \times  35.3  =  341~W [1]

If this hair dryer were to be used in the USA then the holidaymaker would probably notice that the heat output would be much less than in the UK as it would have much less power [1].

The advantages of a lower mains voltage would be that it would be safer with less risk of fatal electrocution. The disadvantages would be that the currents would be larger requiring thicker cables with more heat loss [1].

Answering tip: Briefly plan the key points you want to include in your answer. For example:

  • calculate the current of the hairdryer in the UK and its resistance
  • calculate the current that this hair dryer would need if connected to the USA mains
  • calculate its power if used in the USA

Sample question 2 - Higher


A student investigated the changes in resistance of a 12 V filament lamp and wrote the following report of the experiment.

A 12 V power supply was connected in series with an ammeter, the lamp and a variable resistor. A voltmeter was connected in parallel with the lamp. Initially the variable resistor was set on its highest setting and readings were taken from the ammeter and voltmeter. The setting on the variable resistor was changed 6 times and the readings were taken from the meters each time.

The student did not write anything more. Your task is to complete the report. [6 marks]

Question courtesy of Eduqas.

Circuit with a battery, variable resistor, lamp, ammeter and a voltmeter connected in parallel to the lamp.

Resistance (in Ohms) is calculated each time by dividing the voltage (read from the voltmeter in volts) by the current (from the ammeter in amps) [1]. The results would show that as the voltage is increased, the resistance stays constant for low voltages [1] and then increases as the voltage gets bigger and bigger [1]. Sketch a graph with current on the y-axis [1] and voltage on the x-axis [1]. The graph is initially straight and then curves, showing a decreasing gradient [1].

Answering tip: Briefly plan the key points you want to include in your answer. For example:

  • a circuit diagram from the description given by the student
  • an explanation of how the results should be used to obtain resistance values
  • a sketch graph of how the current through the lamp would change with increasing voltage
  • a brief description of how the resistance of the lamp would change with increasing voltage (not why it changes)