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Ohm's Law 1

Take me to the 'Year 8 Microcontrollers' main course page.

Learning aim

To understand the relationship between voltage, current and resistance (known as 'Ohm's Law').

(Why am I doing this?)

So that I can begin to make predictions about how electrical circuits function.
So in future, I may be able to fix, repair or even design my own simple circuits.

Lesson vocabulary

Voltage

noun: voltage; plural noun: voltages

an electro-motive force (EMF), or potential difference, expressed as volts. It can be thought of as an 'electrical pressure' which causes electrons to be pushed around a circuit.
by Ohm's law, voltage (measured in volts) is equal to the current multiplied by the resistance.

Current

noun: current; plural noun: currents

a flow of electricity which results as a result of the orderly movement of electrons around an electrical circuit. Current is the result of a voltage (potential difference or EMF). When there is no voltage, there can be no current.
by Ohm's law, current (measured in amperes or amps) is equal to the voltage divided by the resistance.

Resistance

noun: resistance; plural noun: resistances

the magnitude (amount) of which a substance or device opposes the passage of an electric current, causing energy dissipation.
by Ohm's law, resistance (measured in ohms) is equal to the voltage divided by the current.

Here are some extra facts for you.

Whilst Amps (Amperes) measures the flow of electrical current, it is fundamentally a measure of the amount of electrical charge being passed between two points. Since the unit of electrical charge is called the 'Coulomb', Amps measures Coulombs per second. A single electron carries 1.60 x 10-19 coulombs of electrical charge. 1 Amp is equal to 1 Coulomb per second. This means that 6.24 × 10¹⁸ electrons moving past a point for every amp! If you can't visualise that number, it is:
six quintillion, two hundred and forty quadrillion electrons per second, pass through a wire - for every amp of current. That's how small electrons are!

Electronic Circuit Simulator

You will use this simulator to build simple DC circuits, which will help build your understanding of how electricity behaves and how understanding Ohm's Law helps us control the current flow in the circuit to make it 'work for us'. Click here to view FULL SCREEN

You will need to take screenshots periodically. To do this, press 'PRINT SCREEN' and then 'CTRL + V' to paste the image into your work.

Understanding &
Calculating 'Ohm's Law'

Consider the Ohm's Law triangle below. To use it, we 'cover up' the thing we want to find. What is left behind represents the formula we must use to calculate it.

Lesson 3 - Task list

If you're feeling confident, have a go at answering the questions on the 'calculations sheet' below. Remember to make a copy (and edit that).

If you are less confident and would rather have some additional support, have a go at this calculation sheet instead.

I don't mind which version of the worksheet you attempt, as long as you attempt all four questions.

When finished, attach it to the Google Classroom for feedback.

Ohm's Law Exercises - More Confident

Lesson 4 - Task list

Make a copy of the 'what I learned today' template.
Using at least 66 words (or a maximum of 72), summarise the Ohm's Law relationship. between voltage, current and resistance.
When finished, attach it to the Google Classroom for feedback.

What I learned today

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