Switch Open,Switch Closed

Electricity and Magnetism Level 1

A battery has an EMF (Electromotive Force ) of \(\displaystyle 6\text{ V}\) and an internal resistance of \(\displaystyle 0.4 \ Ω\). It is connected to a \(\displaystyle 2.6\ Ω\) resistor through a SPST (single pole, single throw) switch.

Find the potential difference between the terminals of the battery when the switch is open and when the switch is closed, in volts.