The cell in the circuit has an emf of 2.0 V. When the variable resistor has a resistance of 4.0 Ω, the potential difference (pd) across the terminals of the cell is 1.0 V.
What is the pd across the terminals of the cell when the resistance of the variable
resistor is 12 Ω?
[1 mark]
The answer is 1.5 V
I've got no Idea how they got there, please would someone help?