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Subjects · Leaving Cert Physics & Chemistry

Leaving Cert Physics & Chemistry: Electrostatics & capacitance

How often Electrostatics & capacitance 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 9 of the last 9 Ordinary Level papers, most recently in 2025. banker

Electrostatics & capacitance, Higher Level(8 marks)

Quick ones on Electrostatics & capacitance.

(a)Two point charges are each doubled and their separation is doubled. The force between them…
  1. Doubles
  2. Stays the same
  3. Becomes four times bigger
(b)Why do the leaves of a gold-leaf electroscope spread apart when it is charged?
  1. Opposite charges on the leaves attract the case
  2. The leaves become magnetised
  3. Both leaves carry the same charge and repel
(c)An earthed electroscope is charged by induction using a negatively charged rod. The final charge on it is…
  1. Positive
  2. Zero
  3. Negative
Show the answers

(a) Stays the same

(b) Both leaves carry the same charge and repel

(c) Positive

Your turn: Higher Level questions on Electrostatics & capacitance.

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(o)
2024Q1(n), Q6(b)
2023Q1(l), Q6(c)
2022Q1(l), Q1(m), Q1(n)
2021Q1(l), Q1(m), Q1(n)
2019Q1(l), Q6(b)
2018Q1(k), Q1(m)
2017Q6(d)
2016Q1(j), Q1(k)

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

More Electrostatics & capacitance questions

Electrostatics & capacitance, 3 marks

A 10 μF capacitor stores 50 μC of charge. Voltage across it?

  1. 500 V
  2. 0.2 V
  3. 5 V
Show the answer

5 V

V = Q/C = 50 μC ÷ 10 μF = 5 V. The micro prefixes cancel. 500 multiplies Q by C; 0.2 is C ÷ Q.

Electrostatics & capacitance, 3 marks

Why does a balloon charged by rubbing stick to an uncharged wall?

  1. Air pressure holds it on once the air behind is pushed out
  2. It induces opposite charge on the wall, which it attracts
  3. The wall is magnetic and pulls on the charged rubber
Show the answer

It induces opposite charge on the wall, which it attracts

The charged balloon repels like charges in the wall surface away slightly, leaving opposite charge nearest it. Opposite charges attract, and the nearer charge wins.

Electrostatics & capacitance, 2 marks

Capacitors of 2 μF and 5 μF are connected in parallel. Total capacitance?

  1. 7 μF
  2. 1.4 μF
  3. 10 μF
Show the answer

7 μF

Capacitors in parallel add: C = C₁ + C₂ = 7 μF. 1.4 μF is the series value (1/C = 1/2 + 1/5); 10 multiplies them.

Ordinary Level

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

Every paper, year by year

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

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

More Electrostatics & capacitance questions

Electrostatics & capacitance, 2 marks

Unit of electric charge?

  1. Ampere
  2. Volt
  3. Coulomb
Show the answer

Coulomb

Charge is measured in coulombs (C). The ampere is the unit of current, a flow of 1 coulomb per second.

Electrostatics & capacitance, 2 marks

Two negative charges are placed close together. They?

  1. Have no effect on each other
  2. Repel
  3. Attract
Show the answer

Repel

Like charges repel; unlike charges attract. The electrons on each one push away from the other.

Electrostatics & capacitance, 2 marks

Coulomb's law: the force between two point charges is inversely proportional to?

  1. The square of the distance between them
  2. The simple distance between the charges
  3. The product of the charges on them
Show the answer

The square of the distance between them

F ∝ q1 q2 ÷ d². The force is proportional to the product of the charges and inversely proportional to the distance squared.

Other Physics & Chemistry topics

All of Leaving Cert Physics & Chemistry