Level 4 · Science S4.12
Circuits and Ohm's law
Current, voltage and resistance are linked, and this lets us design and fix circuits.
Planned. This book is not written yet. Below is its plan, which a teacher can already use.
You are ready for this book if
You can draw a series circuit and a parallel circuit and say how they differ.
- One step up S5.14 Electric circuits and capacitors
- This book S4.12 Circuits and Ohm's law
- One step down S3.10 Electricity and magnetism
The plan
- S4.12.1 Charge and current
- Calculate charge from current and time
- Explain current in metals as a flow of electrons
- S4.12.2 Potential difference
- Explain potential difference as energy transferred per unit of charge
- Connect a voltmeter in parallel and an ammeter in series
- S4.12.3 Ohm's law
- Use V equals I times R in calculations
- Plot a graph of current against voltage for a resistor
- S4.12.4 Different components
- Compare current and voltage graphs for a resistor, a lamp and a diode
- Explain how thermistors and light dependent resistors work in sensors
- S4.12.5 Series circuits
- Calculate total resistance in series
- Explain how voltage is shared in a series circuit
- S4.12.6 Parallel circuits
- Explain how current splits between parallel branches
- Explain why adding resistors in parallel lowers the total resistance
- S4.12.7 Power in circuits
- Calculate power using P equals I times V and I squared times R
- Choose the right fuse for an appliance
- S4.12.8 Mains electricity and safety
- Explain the difference between direct and alternating current
- Explain the jobs of the live, neutral and earth wires and the fuse
- Explain why mains electricity is never used for home experiments
For parents and teachers
Level 4 fits learners who can already: follow a written argument. use letters for numbers. In many schools that is about 14 to 16, but start wherever the learner is.
Strand: Electricity and magnetism. Written and drawn by attnom. Free to read, print and share.