Magnetic fields: past paper questions
Real questions on magnetic fields
The newest 20 of 231 written questions. Open one to see it on the real paper.
- 9702/41 · October/November 2025 · Q7a[2]
State Faraday’s law of electromagnetic induction.
See it on the paper → - 9702/41 · October/November 2025 · Q7b(i)[2]
Calculate the magnetic flux cut by the wings of the aircraft in a time of 15 s. Give a unit with your answer. magnetic flux = unit
See it on the paper → - 9702/41 · October/November 2025 · Q7b(ii)[2]
Determine the area of flux cut by the wings in a time of 15 s. area = m 2
See it on the paper → - 9702/41 · October/November 2025 · Q7b(iii)[2]
Use your answer in (b)(ii) to determine the speed v of the aircraft. v = m s –1
See it on the paper → - 9702/41 · October/November 2025 · Q7b(iv)[3]
Use Lenz’s law of electromagnetic induction to explain which of the wingtips P and Q is at the higher induced potential.
See it on the paper → - 9702/43 · October/November 2025 · Q7a[2]
State Faraday’s law of electromagnetic induction.
See it on the paper → - 9702/43 · October/November 2025 · Q7b(i)[2]
Calculate the magnetic flux cut by the wings of the aircraft in a time of 15 s. Give a unit with your answer. magnetic flux = unit
See it on the paper → - 9702/43 · October/November 2025 · Q7b(ii)[2]
Determine the area of flux cut by the wings in a time of 15 s. area = m 2
See it on the paper → - 9702/43 · October/November 2025 · Q7b(iii)[2]
Use your answer in (b)(ii) to determine the speed v of the aircraft. v = m s –1
See it on the paper → - 9702/43 · October/November 2025 · Q7b(iv)[3]
Use Lenz’s law of electromagnetic induction to explain which of the wingtips P and Q is at the higher induced potential.
See it on the paper → - 9702/42 · May/June 2025 · Q2b(i)[1]
On Fig. 2.3, label the magnetic poles with the letters N and S to indicate which one is the magnetic N pole and which one is the magnetic S pole.
See it on the paper → - 9702/42 · May/June 2025 · Q2b(ii)[2]
On Fig. 2.3, draw field lines to represent the Earth’s magnetic field outside the Earth.
See it on the paper → - 9702/42 · May/June 2025 · Q2c(ii)[3]
With reference to your answer in (b)(ii), describe how the observed magnetic field of the Earth varies around the surface.
See it on the paper → - 9702/51 · May/June 2025 · Q1[6]
l S Fig. 1.1 An alternating voltage is applied to the terminals. The peak value of the alternating voltage is E and the frequency is f. The peak value of the potential difference V across the resistor is determined using an oscilloscope. It is suggested that V is related to f by the relationship ES KAN 2 f = V l where...
See it on the paper → - 9702/53 · May/June 2025 · Q1[6]
l S Fig. 1.1 An alternating voltage is applied to the terminals. The peak value of the alternating voltage is E and the frequency is f. The peak value of the potential difference V across the resistor is determined using an oscilloscope. It is suggested that V is related to f by the relationship ES KAN 2 f = V l where...
See it on the paper → - 9702/42 · February/March 2025 · Q7a[2]
State Faraday’s law of electromagnetic induction.
See it on the paper → - 9702/42 · February/March 2025 · Q7b(i)[2]
Explain how Fig. 7.2 shows that E is proportional to the velocity v of the rod.
See it on the paper → - 9702/42 · February/March 2025 · Q7b(ii)[3]
Use Faraday’s law to show that the variation of E with time t is given by E = Blat where a is the acceleration of the rod.
See it on the paper → - 9702/42 · February/March 2025 · Q7b(iii)[2]
The length of the rod is 0.45 m. The acceleration a of the rod is 7.8 m s –2 . Determine the value of B. B = T
See it on the paper → - 9702/41 · October/November 2024 · Q7a[2]
Define magnetic flux density.
See it on the paper →
What examiners said
Faraday’s law of electromagnetic induction was generally well-known, and full credit was common.
— Examiner report, February/March 2025, 9702/42 Q7(a) (Cambridge)
A large proportion of the weaker candidates missed the point of this question and focussed solely on the trend of Figure 7.2. The candidates who were successful in answering this question spotted that, whilst Figure 7.2 concerns the relationship between E and t, the question was about the relationship between E and v. The starting point for answering correctly required the direct proportionality b...
— Examiner report, February/March 2025, 9702/42 Q7(b)(i) (Cambridge)
This challenging derivation required candidates to think of the scenario of the rod moving a short distance ∆x in a short time ∆t. Many candidates conflated t with ∆t and were thus unable to produce a derivation based on correct physics.
— Examiner report, February/March 2025, 9702/42 Q7(b)(ii) (Cambridge)
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