levo

Sensing

Current and the flow of charge

  • 3 things to know
  • Components 01, 02 and 03

Overview

Recall questions on current as the rate of flow of charge, I = ΔQ/Δt, the coulomb, charge carriers in metals and electrolytes, counting electrons, conventional current, the same current around a series circuit, why a lamp lights at once, I = nAvq and drift speed in a narrowing wire, and why current is a scalar.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

Define electric current.

Key term

State the relationship between current, charge and time.

Key term

What carries the current in an electrolyte?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    Define electric current.

    Model answer

    Electric current is the rate of flow of electric charge.

  2. 2

    State the relationship between current, charge and time.

    Model answer

    I = ΔQ/Δt, giving the current in amperes when the charge is in coulombs and the time in seconds.

  3. 3

    What are the mobile charge carriers in a metal?

    Model answer

    They are the delocalised, or free, electrons.

  4. 4

    What carries the current in an electrolyte?

    Model answer

    Positive and negative ions, moving in opposite directions through the solution.

  5. 5

    Define the coulomb.

    Model answer

    One coulomb is the charge that passes a point when a current of one ampere flows for one second.

  6. 6

    A charge of 240 C passes through a lamp in 2.0 minutes. Calculate the current.

    Model answer

    I = 240/120 = 2.0 A.

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.

Planning
Implementing
Analysis
Evaluation

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 two charges .
attractrepelcombine

Blank Blitz makes facts automatic

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

AThe neutron has lepton number 0.
BOn the other side the proton has 0.
CThe electron has +1 and the antineutrino has −1.

Build It gets the exam shape right

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

There are 2π rad in a full circle.
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 Sensing, 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.