AQA GCSE Series Circuit (Combined Science)

Series Circuit

A series circuit is a single loop circuit, and the components are connected along a single path, end to end.

Series circuit with two bulbs

Above is an example of a series circuit with two bulbs.

Series Circuit Rules

Rule 1: In a series circuit, the current is the same at all points. 

Current in a series circuit is the same at all points

In the above circuit the current is at 5 Amps at all 3 ammeters.

Rule 2: In a series circuit the potential difference is shared between the components.

Potential difference being shared in a series circuit

In the above circuit, the 10V potential difference across the cell is shared between the two bulbs equally. So the potential difference across each bulb is 5V

Rule 3: The total resistance in a series circuit is the sum of the individual resistors. 

Calculating total resistance in a series circuit

In the above circuit, there are two 5 ohm resistors. So, the total resistance is 10 ohms. 

Practice Questions

1.State the value for the current for ammeter A1 in the circuit below:

Question on current in a series circuit

2. Calculate the potential difference across the cell for voltmeter V1, using the cell diagram below.

Calculating potential difference in a series circuit

3. The total resistance of a series circuit is 35 ohms. There are 3 resistors in series, that each have their own resistance value in the ratio of 4:2:1. Calculate the resistance of each resistor.