Key term
AQA GCSE Combined Science Physics 8464
Atomic Structure
Topic overviewThe structure of an atomMass number, atomic number and isotopesFrom the plum pudding model to the nuclear modelChadwick, the neutron, and comparing the modelsRadioactive decay and nuclear radiationNuclear equationsHalf-lives and the random nature of radioactive decayRadioactive contamination
Electricity
Topic overviewCircuit symbols, electrical charge and currentCurrent, resistance and potential differenceOhmic conductors, filament lamps, diodes and thermistorsLight-dependent resistors, and investigating resistanceCurrent and potential difference in series and parallelConstructing circuits, and calculating in series circuitsDirect and alternating potential difference, and mains electricityPower and efficiencyAppliances, and the energy transferred by electrical workPower, and the power ratings of domestic appliancesThe National Grid
Energy
Forces
Topic overviewScalars, vectors, forces and the resultant forceGravityWork done and energy transferStretching, compressing, and the spring constantLinear and non-linear extension, and work done on a springDistance, displacement and speedThe speed of sound, and the distance-speed-time equationVelocity and the distance-time relationshipAcceleration, deceleration and velocity-time graphsArea under a velocity-time graph, and the uniform acceleration equationNewton's First LawNewton's Second and Third LawsStopping distance and reaction timeFactors affecting braking distanceBraking force, deceleration and the dangers of stopping quickly
Magnetism and Electromagnetism
Particle Model of Matter
Electricity
Ohmic conductors, filament lamps, diodes and thermistors
- 3 things to know
- Physics Paper 1
Overview
Constant and changing resistance, ohmic conductors at constant temperature and calculations with them, components whose resistance is not constant, why the resistance of a filament lamp rises as it heats, current against potential difference graphs for lamps and diodes, one-way current through a diode, and thermistors in thermostats and other uses.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Numbers
A resistor at constant temperature carries 0.2 A when 4 V is applied. Calculate the current when 10 V is applied.
Key term
Name four components whose resistance is not constant.
Questions from this subtopic
Each one with the model answer underneath.
- 1
What is meant by saying that some resistors have a constant resistance while others do not?
Model answer
In some the resistance keeps the same value however much current flows, while in others the resistance changes as the current changes.
- 2
Two resistors are tested over a range of currents and only one keeps the same value of potential difference divided by current. What does this tell you about the other?
Model answer
Its resistance is not constant, so it changes as the current through it changes.
- 3
What is the relationship between current and potential difference for an ohmic conductor at constant temperature?
Model answer
The current is directly proportional to the potential difference.
- 4
The potential difference across an ohmic conductor at constant temperature is trebled. What happens to the current?
Model answer
It is also trebled.
- 5
Explain why the resistance of an ohmic conductor stays the same as the current changes.
Model answer
Because the potential difference rises in the same ratio as the current, so potential difference divided by current is unchanged.
- 6
What condition must be met for a resistor to behave as an ohmic conductor?
Model answer
Its temperature must stay constant.
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 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.