How to calculate voltage drop with internal resistance and load values
There is only one current loop, so the magnitude of current will be 5A throughout the circuit.
As there will be 5A through the internal 2ohm load, apply Ohm's Law (V=IR) to calculate the voltage dropped across the resistor.
This shows a voltage of 10V will be dropped across the internal resistance, leaving no voltage for the current sink. If this is a serious and correct question, the answer is that 0V are available at the current sink - i.e. your battery has completely browned out, leaving no voltage for the load.