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Subjects · Leaving Cert Physics & Chemistry

Leaving Cert Physics & Chemistry: Induction & transformers

How often Induction & transformers comes up on the Physics & Chemistry papers, every year it was asked, and questions to try.

HL Asked on 9 of the last 9 Higher Level papers, most recently in 2025. banker

OL Asked on 8 of the last 9 Ordinary Level papers, most recently in 2025. most years

Induction & transformers, Higher Level(8 marks)

Quick ones on Induction & transformers.

(a)Faraday's law: the size of the induced emf is proportional to…
  1. The strength of the magnet only
  2. The rate of change of magnetic flux
  3. The resistance of the coil
(b)A transformer has 2300 turns on the primary and steps 230 V down to 12 V. Secondary turns?
  1. 44,083
  2. 1200
  3. 120
(c)Why is a transformer core laminated?
  1. To reduce eddy currents and heat loss
  2. To make the core a permanent magnet
  3. To increase the current in the secondary
Show the answers

(a) The rate of change of magnetic flux

(b) 120

(c) To reduce eddy currents and heat loss

Your turn: Higher Level questions on Induction & transformers.

Higher Level

Asked on 9 of the last 9 Higher Level papers, most recently in 2025. banker

Every paper, year by year

YearWhere it came up
2025Q1(m), Q6(c)
2024Q1(o), Q5
2023Q1(o), Q1(p), Q5
2022Q6(c)
2021Q1(o), Q1(p)
2019Q1(j), Q1(m), Q5
2018Q5
2017Q1(m)
2016Q1(m), Q5

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

More Induction & transformers questions

Induction & transformers, 2 marks

Electromagnetic induction is…

  1. Magnetising a piece of iron by passing a current round it
  2. The force on a current-carrying conductor in a magnetic field
  3. An emf produced in a conductor by a changing magnetic flux
Show the answer

An emf produced in a conductor by a changing magnetic flux

Moving a magnet near a coil (or changing the current in a nearby coil) changes the flux, which induces an emf. The force on a current is the motor effect.

Induction & transformers, 3 marks

An a.c. generator (alternator) connects its spinning coil to the outside circuit using…

  1. A fuse
  2. Slip rings
  3. A split-ring commutator
Show the answer

Slip rings

Slip rings keep each end of the coil joined to the same brush, so the output alternates. A split ring reverses the connections each half turn, giving d.c.

Induction & transformers, 2 marks

Frequency of the mains a.c. supply in Ireland?

  1. 50 Hz
  2. 60 Hz
  3. 230 Hz
Show the answer

50 Hz

The Irish and European mains alternates at 50 Hz: 50 complete cycles each second. 230 is the voltage, not the frequency.

Ordinary Level

Asked on 8 of the last 9 Ordinary Level papers, most recently in 2025. most years

Every paper, year by year

YearWhere it came up
2025Q1(n)
2024Q1(o)
2023Q6(b)
2022Q6(c)
2021Q6(d)
2019Q1(k)
2018Q5
2017Not asked
2016Q5

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

More Induction & transformers questions

Induction & transformers, 2 marks

Faraday's law: the induced emf is proportional to?

  1. The resistance of the coil's wire
  2. The temperature of the coil and magnet
  3. The rate of change of magnetic flux
Show the answer

The rate of change of magnetic flux

Move a magnet faster, or use more turns, and the induced voltage is bigger. No change in flux means no induced emf.

Induction & transformers, 2 marks

A transformer only works with?

  1. Static charge
  2. Alternating current
  3. Direct current
Show the answer

Alternating current

Only a changing current in the primary gives a changing magnetic field in the core, which induces a voltage in the secondary.

Induction & transformers, 3 marks

A transformer has 2000 primary turns and 200 secondary turns. Input 230 V. Output voltage?

  1. 23 V
  2. 2300 V
  3. 115 V
Show the answer

23 V

Vs ÷ Vp = Ns ÷ Np, so Vs = 230 × 200 ÷ 2000 = 23 V. Fewer turns on the secondary means a step-down transformer.

Other Physics & Chemistry topics

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