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Leaving Cert Physics: Mandatory experiments

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

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

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.

Mandatory experiments, Higher Level(8 marks)

Quick ones on Mandatory experiments.

(a)In the free-fall experiment to measure g, what is plotted and what does the slope give?
  1. s against t, and the slope equals g
  2. s against t², and the slope equals g/2
  3. t against s, and the slope equals 2g
(b)In the verification of Ohm's law, what does the slope of the voltage against current graph give?
  1. The current through the conductor
  2. The power dissipated in the conductor
  3. The resistance of the conductor
(c)In the simple pendulum experiment to find g, what graph is drawn?
  1. T² against length, and g = 4π² divided by the slope
  2. T² against length squared, and the slope equals 4π²/g
  3. T against length, and the slope equals g
Show the answers

(a) s against t², and the slope equals g/2

(b) The resistance of the conductor

(c) T² against length, and g = 4π² divided by the slope

Your turn: Higher Level questions on Mandatory experiments.

Higher Level

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

Every paper, year by year

YearWhere it came up
2026Q1, Q2, Q3, Q4, Q5
2025Q1, Q2, Q3, Q4, Q5
2024Q1, Q2, Q3, Q4, Q5
2023Q1, Q2, Q3, Q4, Q5
2022Q1, Q2, Q3, Q4, Q5
2021Q1, Q2, Q3, Q4, Q5
2019Q1, Q2, Q3, Q4
2018Q1, Q2, Q3, Q4
2017Q1, Q2, Q3, Q4
2016Q1, Q2, Q3, Q4

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

More Mandatory experiments questions

Mandatory experiments, 3 marks

What apparatus is used to verify the principle of conservation of momentum?

  1. A calorimeter, a joulemeter, a heating coil and a thermometer
  2. A spring balance, a pulley and a set of slotted masses
  3. Two trolleys on a level track with light gates and timers
Show the answer

Two trolleys on a level track with light gates and timers

Trolleys of known mass run on a friction-compensated or air track, and light gates give the velocities before and after the collision so mv can be compared.

Mandatory experiments, 3 marks

In the verification of Joule's law, what graph is drawn?

  1. Temperature rise against time, giving a straight line with a positive slope
  2. Temperature rise against current squared, giving a straight line through the origin
  3. Temperature rise against current, giving a straight line through the origin
Show the answer

Temperature rise against current squared, giving a straight line through the origin

Joule's law says the heat produced is proportional to I² for a fixed resistance and time, so Δθ against I² is a straight line through the origin.

Mandatory experiments, 2 marks

Verifying Newton's second law with the mass kept constant: which graph is a straight line through the origin?

  1. Acceleration against resultant force
  2. Acceleration against mass
  3. Velocity against resultant force
Show the answer

Acceleration against resultant force

F = ma, so with m fixed a ∝ F and the slope is 1/m. Acceleration against mass would give a curve (a ∝ 1/m for a fixed force).

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
2026Q1, Q2, Q3, Q4, Q5
2025Q1, Q2, Q3, Q4, Q5
2024Q1, Q2, Q3, Q4, Q5
2023Q1, Q2, Q3, Q4, Q5
2022Q1, Q2, Q3, Q4, Q5
2021Q1, Q2, Q3, Q4, Q5
2019Q1, Q2, Q3, Q4
2018Q1, Q2, Q3, Q4
2017Q1, Q2, Q3, Q4
2016Q1, Q2, Q3, Q4

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

More Mandatory experiments questions

Mandatory experiments, 3 marks

Latent heat of vaporisation of water: why is the steam passed through a steam trap?

  1. To heat the steam further
  2. To measure the mass of the steam
  3. To remove any water that has condensed
Show the answer

To remove any water that has condensed

Only dry steam must reach the calorimeter. Condensed water would add mass without giving out latent heat.

Mandatory experiments, 2 marks

Stretched string and length: how do you know the string is vibrating at its fundamental frequency?

  1. The tuning fork stops humming as soon as it touches the bridge
  2. A paper rider placed on the middle of the string falls off
  3. A paper rider placed at one end of the string falls off
Show the answer

A paper rider placed on the middle of the string falls off

When the string resonates with the tuning fork it vibrates strongly at its middle, which throws the small paper rider off.

Mandatory experiments, 3 marks

Calibration curve of a thermometer: its thermometric property is plotted against the reading on which thermometer?

  1. The laboratory mercury thermometer
  2. A digital clinical thermometer
  3. A thermocouple joined to a voltmeter
Show the answer

The laboratory mercury thermometer

The mercury thermometer is taken as the standard. The curve then lets you read any temperature from the new thermometer.

Other Physics topics

All of Leaving Cert Physics