If no internal resistance is present in voltage supply, the potential difference across the resistor is equal to supply voltage. Now imagine the same circuit but total current is given as 0.1A . The potential difference is V=IR=0.1*5=0.5V, which basically means the statement above is incorrect.
What happens when you increase the potential difference?
Current, potential difference and resistance. The size of the current flowing in a circuit depends on the potential difference (voltage) driving it and the amount of resistance it has to flow through. For a fixed resistance the amount of current increases with increasing potential difference.
Is the potential difference the same in a parallel circuit?
In parallel circuits, the electric potential difference across each resistor (ΔV) is the same. In a parallel circuit, the voltage drops across each of the branches is the same as the voltage gain in the battery. Thus, the voltage drop is the same across each of these resistors.