levo

Conduction of Electricity

Electric charge and the coulomb

  • 3 things to know
  • Component 2

Overview

SI unit of electric charge, magnitude of the charge carried by a single electron and saying that charge is quantised.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What is the SI unit of electric charge, and what symbol is used for it?

Key term

State the magnitude of the charge carried by a single electron.

Key term

Why is the coulomb described as a very large unit of charge?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What is the SI unit of electric charge, and what symbol is used for it?

    Model answer

    Electric charge is measured in the coulomb, and its symbol is C.

  2. 2

    State the magnitude of the charge carried by a single electron.

    Model answer

    An electron carries a charge of magnitude 1.60 × 10⁻¹⁹ C.

  3. 3

    Why is the coulomb described as a very large unit of charge?

    Model answer

    One coulomb is the combined charge of about 6.25 × 10¹⁸ electrons, so the charge on one electron is a minute fraction of it.

  4. 4

    How many electrons must pass a point for a total charge of 1.0 C to be transferred?

    Model answer

    The number is 1.0 ÷ (1.60 × 10⁻¹⁹) = 6.3 × 10¹⁸ electrons.

  5. 5

    State the sign and value of the charge on an electron and on a proton.

    Model answer

    The electron carries −1.60 × 10⁻¹⁹ C and the proton carries +1.60 × 10⁻¹⁹ C.

  6. 6

    A small metal sphere carries a charge of −4.8 × 10⁻¹⁷ C. How many excess electrons does it hold?

    Model answer

    The number is (4.8 × 10⁻¹⁷) ÷ (1.60 × 10⁻¹⁹) = 300 excess electrons. Multiplying 300 by 1.60 × 10⁻¹⁹ C returns the stated charge.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Basic Physics
Kinematics
Dynamics
Energy Concepts

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

The wires .
attractrepeltwist

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AThe equation is pV = NkT.
BThe pressure, p, is in Pa.
CThe volume V is in m³.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

The joule is a unit of energy.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Conduction of Electricity, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.