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Leaving Cert Physics: Magnetic fields

How often Magnetic fields comes up on the Physics papers, every year it was asked, and questions to try.

HL Asked on 4 of the last 10 Higher Level papers, most recently in 2024.

OL Asked on 10 of the last 10 Ordinary Level papers, most recently in 2026. banker

June 2027 is the first exam on the new Physics course. These come from the 2016–2026 papers, so read them as a guide.

Magnetic fields, Higher Level(6 marks)

Quick ones on Magnetic fields.

(a)SI unit of magnetic flux density?
  1. Weber (Wb)
  2. Tesla (T)
  3. Henry (H)
(b)SI unit of magnetic flux?
  1. Ampere metre (A m)
  2. Tesla (T)
  3. Weber (Wb)
(c)Shape of the magnetic field around a long straight current-carrying wire?
  1. Concentric circles around the wire
  2. Straight lines pointing radially outwards
  3. Straight lines parallel to the wire
Show the answers

(a) Tesla (T)

(b) Weber (Wb)

(c) Concentric circles around the wire

Your turn: Higher Level questions on Magnetic fields.

Higher Level

Asked on 4 of the last 10 Higher Level papers, most recently in 2024.

Every paper, year by year

YearWhere it came up
2026Not asked
2025Not asked
2024Q8
2023Not asked
2022Not asked
2021Q10
2019Q9
2018Q9
2017Not asked
2016Not asked

Links open the State Examinations Commission’s paper for that year.

More Magnetic fields questions

Magnetic fields, 3 marks

Force on an electron moving at 2.0 × 10⁶ m s⁻¹ at right angles to a 0.50 T field? (e = 1.6 × 10⁻¹⁹ C)

  1. 6.4 × 10⁻¹³ N
  2. 1.6 × 10⁻¹⁹ N
  3. 1.6 × 10⁻¹³ N
Show the answer

1.6 × 10⁻¹³ N

F = qvB = 1.6 × 10⁻¹⁹ × 2.0 × 10⁶ × 0.50 = 1.6 × 10⁻¹³ N. The force is at right angles to both the velocity and the field.

Magnetic fields, 3 marks

Why does a magnetic field not change the speed of a charged particle moving at right angles to it?

  1. The particle loses some of its charge while it moves through the field
  2. The force is always at right angles to the velocity, so it does no work
  3. There is no force at all on a charge that moves at right angles to a field
Show the answer

The force is always at right angles to the velocity, so it does no work

The force F = qvB is perpendicular to the motion, so it changes the direction only. The particle moves in a circle at constant speed.

Ordinary Level

Asked on 10 of the last 10 Ordinary Level papers, most recently in 2026. banker

Every paper, year by year

YearWhere it came up
2026Q6(f)
2025Q6(g), Q10
2024Q6(l)
2023Q14(d)
2022Q6(h)
2021Q6(h), Q14(c)
2019Q12(c)
2018Q5(h)
2017Q9
2016Q12(b)

Links open the State Examinations Commission’s paper for that year.

More Magnetic fields questions

Magnetic fields, 2 marks

Direction of the magnetic field lines outside a bar magnet?

  1. From the south pole to the north pole
  2. Straight out from the centre of the magnet
  3. From the north pole to the south pole
Show the answer

From the north pole to the south pole

Field lines leave the north pole and enter the south pole. A plotting compass lines up along them.

Magnetic fields, 2 marks

Why is soft iron used for the core of an electromagnet?

  1. It is a poor conductor of heat, so the coil stays cool
  2. It is easily magnetised and easily loses its magnetism
  3. It keeps its magnetism for a long time after the current stops
Show the answer

It is easily magnetised and easily loses its magnetism

Soft iron makes the field much stronger while the current flows and loses its magnetism when the current is switched off.

Magnetic fields, 2 marks

Which instrument shows the direction of a magnetic field at a point?

  1. A plotting compass
  2. A voltmeter
  3. A thermometer
Show the answer

A plotting compass

A plotting compass is a tiny magnet. Its north pole points along the field line at that point.

Other Physics topics

All of Leaving Cert Physics