Bulb and buzzer in parallel

What the Activity is for

This activity provides the opportunity for pupils to talk and think about a circuit in which there are two components (bulb and buzzer) of unequal resistance. The pupils are directed to set up the parallel circuit and to measure the voltage across each component and relate that to what's happening in the circuit. They must then come up with an explanation for their findings.

What to Prepare

• batteries, bulbs, buzzers, voltmeters, connecting leads
• printed copies of the support sheet: Bulb and buzzer in parallel

Support sheet

What Happens During this Activity

This activity follows on from bulbs and buzzers in series. You might introduce this activity in the following kind of way:

Teacher: OK, so what happened with the circuit with the two bulbs in parallel. What were the voltage readings?

Aarn: The voltage drop across both bulbs was the same as the battery voltage.

Teacher: Good! Now in this circuit we have two components in parallel again, but this time it's a bulb and a buzzer. The plan is for you to set up the circuit, measure the voltage across the different parts and then figure out what's going on.