GCSE Combined Science (AQA)

622 videos | 38 hours

Calculating Resistance

Please subscribe to watch this video.

This, and all other videos, are included in our premium subscriptions.

Premium accounts get access to all videos.

Electricity Current, potential difference and resistance

Calculating Resistance

2:41 Potential Difference and Resistance
Spec 4.2.1.3
Previous Resistance Next Measuring Resistance
  • Current through a component is determined by its resistance and the potential difference across it.
  • The equation for this relationship is potential difference = current x resistance (V = I x R), known as Ohm's Law.
  • Units: potential difference in volts, current in amps, resistance in ohms.
  • Example 1: A component with 1 ohm resistance has a potential difference of 1 volt when 1 amp of current flows through it.
  • Example 2: For a variable resistor set to 15 ohms with a current of 0.2 amps, the potential difference is calculated as 3 volts.
  • Example 3: An electric heater with a potential difference of 230 volts and a current of 5 amps has a resistance of 46 ohms.
  • Steps for calculations:
  • Write down key information and check units.
  • Use the formula to calculate potential difference or rearrange it to find resistance.
  • Substitute values into the formula to get the result.

Please subscribe to access these revision notes.

This, and all other video notes, are included in our premium subscriptions.

Premium accounts get access to all videos and revision notes.