The potential difference in a circuit is 5V. There are two resistors connected in series of resistance 10 Ohms. Calculate the current I in the circuit.

Ohm's law states that V=IR ; where V is p.d., I is current and R is resistance.

Firstly the two resistors are in series so the total resistance is just the sum of the two resistances. Therefore R = 10+10 = 20 Ohms.

The potential difference V is 5V. 

By rearranging Ohm's law for the current I, I=V/R the current can be found by 5/20 = 0.25A

RS

Related Physics GCSE answers

All answers ▸

The teacher quickly inverts the can containing boiling water into a bowl of cold water, as shown in the diagram. When the can is inverted in the cold water, the can collapses. Use ideas about particles and pressure to explain why the can collapses.


A car driver has to make an emergency stop. The braking distance depends on the speed of the car. For the same braking force, what happens to the braking distance if the speed doubles?


How to find wave speed from frequency and wave length.


Why are transformers used in the National Grid?