OCR A-Level Physics B H557
Planning
Implementing
Analysis
Evaluation
Practical Skills
Use of Apparatus and Techniques
Fundamental Data Analysis
Imaging and Signalling
Sensing
Mechanical Properties of Materials
Waves and Quantum Behaviour
Space, Time and Motion
Creating Models
Out Into Space
Our Place in the Universe
Matter: Very Simple
Matter: Hot or Cold
Electromagnetism
Charge and Field
Probing Deep Into Matter
Ionising Radiation and Risk
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.
State the relationship between current, charge and time.
What carries the current in an electrolyte?
Questions from this subtopic
Each one with the model answer underneath.
- 1
Define electric current.
Model answer
Electric current is the rate of flow of electric charge.
- 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
What are the mobile charge carriers in a metal?
Model answer
They are the delocalised, or free, electrons.
- 4
What carries the current in an electrolyte?
Model answer
Positive and negative ions, moving in opposite directions through the solution.
- 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
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.
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.