Question 5
Two wires of different metals are given the same length, the same cross-sectional area and the same potential difference, yet the currents through them differ. Why?
The right answer is the one marked above.
The two metals have different resistivities. Resistivity is a property of the material itself, quite apart from the size and shape of the piece. Different resistivities mean different resistances.
The other three options are all ruled out by the question, which states that the length, the area and the voltage were the same. Only the material was different.