# 4.2.1.3

Current, resistance and potential difference

# 4.2.1.3 Current, resistance and potential difference

## Content

• The current (I) through a component depends on both the resistance (R) of the component and the potential difference (V) across the component. The greater the resistance of the component the smaller the current for a given potential difference (pd) across the component.

Questions will be set using the term potential difference. Students will gain credit for the correct use of either potential difference or voltage.

Current, potential difference or resistance can be calculated using the equation:

potential difference = current × resistance

V=IR

potential difference, V, in volts, V

current, I, in amperes, A (amp is acceptable for ampere) resistance, R, in ohms, Ω

MS 3b Change the subject of an equation

MS 3c Substitute numerical values into algebraic equations using appropriate units for physical quantities

## KS4 -P4.3 Current - Theory

Demo :

• Energy stick
• Rope
• Truck model

### Practical

Demo :

• Energy stick

Practical:

11 x

2 x Bulbs

1 x Spider Power supply

1 x Ammeter