A conducting wire has length l and area of cross-section A. The resistivity of its material is ρ and its wire resistance is R. It is connected in series with another wire of the same dimensions but of a resistivity 2ρ. The net resistance of the combination is
A conducting wire has length l and area of cross-section A. The resistivity of its material is ρ and its wire resistance is R. It is connected in series with another wire of the same dimensions but of a resistivity 2ρ. The net resistance of the combination is
Right Answer is:
3R
SOLUTION
Since the resistivity R is proportional to the resistivity ρ
R = ρL/A
Since all the dimensions are the same
R = ρ
So the resistance of the second wire will become 2R
Resistance in series = R + 2R = 3R