the variable that the person doing the experiment changes

the variable that is measured; it changes as a result of varying the independent variable

a variable that needs to be kept the same to allow a fair test to be carried out

a type of error that affects results in an unpredictable way

describes the relationship between two variables if both increase in the same proportion as each other

Resistance of a wire at a constant temperature

Combined science

In the Circuit components unit, they will build on this knowledge to learn how the resistance of filament lamps and diodes change with current and about the properties and applications of light dependent resistors and thermistors.

In the Resistance and parallel circuits unit, pupils learnt about electrical resistance and parallel electric circuits.

Electric fields and circuit calculations

Physical activity and equipment requiring safe use

A type of error that can affect results in an unpredictable way is called a {{}} error.

A pupil investigates the relationship between the length of a wire and the resistance of the wire. Which of the following are control variables in this investigation?

Connect a voltmeter in series and an ammeter in parallel with the wire.

Connect a voltmeter in parallel and an ammeter in series with the wire.

Connect both a voltmeter and an ammeter in series with the wire.

Connect both a voltmeter and an ammeter in parallel with the wire.

Which of the following statements describes how to connect a voltmeter and ammeter to measure the resistance of a piece of wire in a circuit?

stir the water before taking a measurement

take the thermometer out of the water between measurements

The diagram shows some of the apparatus for investigating the effect of length of a wire on its resistance. Which of the following will help keep the temperature of the wire constant?

increasing the cross-sectional area of the wire

making the wire curved instead of straight

Which of the following increase the resistance of a metal wire?

As they do, they collide with metal ions.

This makes the ions move more (so the temperature of the wire increases).

So it is harder for electrons to flow – the resistance is greater.

Sort the following sentences into the correct order to explain why the resistance of a wire may increase when a current flows in it.

Match the following quantities to its unit symbol.

Which of the following can be used to calculate resistance?

a variable that needs to be kept the same in a fair test

the variable that is measured to get a set of results

the variable that the experimenter selects values for

Match each of the following types of variable to its definition.

When a current flows in a wire, which of the following moves through the wire?

In a graph showing the results of an experiment, where does each type of variable usually appear?

The measured value is different from the true value.

The experimenter did not follow the method correctly.

When there is an error in an experimental measurement, which of the following must be true?

Content guidance

Risk assessment required - equipment

Adult supervision required

Introduction

What will you need for this lesson?

Are you ready to learn?

Equipment

Content guidance

Supervision

Worksheet