Subjects · Leaving Cert Physics
Leaving Cert Physics: Electromagnetic induction
How often Electromagnetic induction comes up on the Physics papers, every year it was asked, and questions to try.
HL Asked on 7 of the last 10 Higher Level papers, most recently in 2026. most years
OL Asked on 4 of the last 10 Ordinary Level papers, most recently in 2026.
June 2027 is the first exam on the new Physics course. These come from the 2016–2026 papers, so read them as a guide.
Quick ones on Electromagnetic induction.
- The conservation of momentum
- The conservation of energy
- The conservation of charge
- The largest emf, because the magnet is closest
- A steady emf, because the flux is large
- None, because the flux is not changing
- The induced current makes a pole that repels it
- The magnet loses its magnetism inside the coil
- The coil's resistance rises as the magnet enters
Show the answers
(a) The conservation of energy
(b) None, because the flux is not changing
(c) The induced current makes a pole that repels it
Higher Level
Asked on 7 of the last 10 Higher Level papers, most recently in 2026. most years
Every paper, year by year
| Year | Where it came up |
|---|---|
| 2026 | Q6(g) |
| 2025 | Q13 |
| 2024 | Not asked |
| 2023 | Q11 |
| 2022 | Q14(d) |
| 2021 | Q10 |
| 2019 | Not asked |
| 2018 | Q9 |
| 2017 | Not asked |
| 2016 | Q10 |
Links open the State Examinations Commission’s paper for that year.
More Electromagnetic induction questions
Electromagnetic induction, 3 marks
State Faraday's law of electromagnetic induction.
- The size of the induced emf is proportional to the magnetic flux through the circuit
- The induced current always flows so as to oppose the change that produces it
- The size of the induced emf is proportional to the rate of change of magnetic flux
Show the answer
The size of the induced emf is proportional to the rate of change of magnetic flux
A faster change of flux means a bigger emf. The last statement is Lenz's law, which gives the direction of the current, not the size of the emf.
Electromagnetic induction, 3 marks
State Lenz's law.
- The induced current flows in the direction of the magnetic field
- The direction of the induced current is such as to oppose the change causing it
- The induced emf is proportional to the rate of change of flux
Show the answer
The direction of the induced current is such as to oppose the change causing it
It follows from the conservation of energy: you must do work against the opposing force to keep the flux changing.
Electromagnetic induction, 2 marks
A generator coil is connected to the outside circuit through slip rings. What does it supply?
- An alternating current
- A direct current
- A steady magnetic field
Show the answer
An alternating current
Slip rings keep each end of the coil joined to the same brush, so the current reverses each half turn: ac. A split-ring commutator would give dc.
Ordinary Level
Asked on 4 of the last 10 Ordinary Level papers, most recently in 2026.
Every paper, year by year
| Year | Where it came up |
|---|---|
| 2026 | Q14(d) |
| 2025 | Q10 |
| 2024 | Not asked |
| 2023 | Not asked |
| 2022 | Not asked |
| 2021 | Not asked |
| 2019 | Not asked |
| 2018 | Q12(d) |
| 2017 | Q9 |
| 2016 | Not asked |
Links open the State Examinations Commission’s paper for that year.
More Electromagnetic induction questions
Electromagnetic induction, 3 marks
What is electromagnetic induction?
- A magnetic field is produced around a wire when a current flows in it
- A magnet loses its magnetism when it is heated strongly or hammered
- An emf is produced in a conductor when the magnetic flux through it changes
Show the answer
An emf is produced in a conductor when the magnetic flux through it changes
Moving a magnet in or out of a coil changes the flux and induces an emf. A current making a field is a different effect.
Electromagnetic induction, 2 marks
A magnet is pushed into a coil. How can the induced emf be made bigger?
- Use fewer turns on the coil
- Push the magnet in faster
- Hold the magnet still in the coil
Show the answer
Push the magnet in faster
Faraday's law: the emf depends on the rate of change of flux. Faster movement, a stronger magnet or more turns all increase it.
Electromagnetic induction, 2 marks
How does an AC generator differ from a DC generator?
- An AC generator uses slip rings; a DC generator uses a split-ring commutator
- An AC generator uses a split-ring commutator; a DC generator uses slip rings
- They are exactly the same
Show the answer
An AC generator uses slip rings; a DC generator uses a split-ring commutator
Slip rings keep each end of the coil joined to the same brush, so the output alternates. A split ring swaps the connections, giving DC.
Other Physics topics
- Diffraction
- Gravity
- Interference
- Magnetic fields
- Mandatory experiments
- Nuclear energy
- Radioactivity
- Refraction
- Resonance
- Sound
- Static electricity
- The photoelectric effect
- Wave properties
- Circuits
- Circular motion
- Density and pressure
- Latent heat
- Linear motion
- Resistance
- Simple harmonic motion
- Work energy and power
- Capacitance
- Doppler effect
- Heat transfer
- Moments
- Momentum
- Reflection
- Semiconductors
- The motor effect
- X-rays
- Colour of light
- Domestic electricity
- Heat capacity
- Newton's laws
- Temperature
- The atom
- The electron
- Current electricity
- Forces
- Lenses
- Thermometers
- Alternating current
- The electromagnetic spectrum
- Transformers