Systems : Electrical Circuit Primary 5 (Mr Vikineesh)

True or False?

Systems are made up of different parts that work together to perform a function.

• True

• False

Answer explanation

Systems are made up of different parts. They parts work together to perform a function. Each of these parts have a specific function.

A _______ is a source of electrical energy. It has 2 terminals - A positive terminal and a negative terminal.

Answer explanation

The battery is part of an electrical circuit. It is the source of electric current that is required for the bulb to light up.

I connect the two terminals of the battery to other electrical parts so that electric current can flow through the circuit. Who am I?

• Battery

• Switch

• Bulb

• Wire

Answer explanation

Wires help to connect the two terminals of the battery to other electrical parts so that electric current can flow through the circuit.

Usually made of copper.

a) Is this an open or closed circuit?

b) Why does the bulb not light up? (Explain)

Answer explanation

It is an open circuit. When there are gaps in the circuit, the electric current is unable to flow through all the components. As such, the bulb does not light up.

In this image, the bulb lights up because there are no gaps. Electrical current is able to flow through all components of the circuit. This is called a closed circuit.

Tom constructed 3 circuits (A, B and C) as shown in the diagram. Based on your understanding, arrange the circuits in order of the brightness of the bulb, starting with the least bright.

• A, B and C

• B, A and C

• C, B and A

• C, A and B

Answer explanation

The brightness of the bulb increases when the number of batteries arranged in series increases. There is more electrical current when there are more batteries.

Sarah constructed 3 circuits (A, B and C) as shown in the diagram. Arrange the circuits in order of the brightness of the bulbs, starting with the least

bright.

• A, B and C

• A, C and B

• C, B and A

• B, A and C

Answer explanation

The brightness of the bulbs decreases when the number of bulbs arranged in series in a circuit increases. Circuit C has the most number of bulbs. The electrical current is shared between 3 bulbs.

This circuit is arranged in _________

• Series

• Parallel

This circuit is arranged in __________

• Series

• Parallel