Q6 · 2021 · Paper 2Simple familiar4 marks
QUESTION 6 (4 marks)
The diagram shows the magnetic field lines inside a solenoid carrying a current of 2 A.
a)[3 marks]
Calculate the number of turns per metre that would produce a magnetic field strength of 300 µT at Point P.
b)[1 mark]
Determine the direction of the magnetic field produced by the solenoid.
WORKED SOLUTION
4 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
𝐵= 𝜇0𝑛𝐼
𝑛= 𝐵
𝜇0𝐼
𝑛= 300 × 10−6
4𝜋× 10−7 × 2 = 119 turns m−1
Left to right
• recognises the scenario relates to the magnetic
field produced inside a solenoid [1 mark]
• provides appropriate mathematical reasoning
[1 mark]
• calculates the number of turns [1 mark]
• determines the field goes from left to right
[1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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