A wire of cross-sectional area 0.60mm2 has a restivity of 7.2 x 10-7 \(\Omega\). Calculate the length of wire that will have a resistance of 3\(\Omega\).
A wire of cross-sectional area 0.60mm2 has a restivity of 7.2 x 10-7 \(\Omega\). Calculate the length of wire that will have a resistance of 3\(\Omega\).
Answer Details
The formula for calculating resistance is R = ρ(L/A), where R is the resistance of the wire, ρ is the resistivity of the wire material, L is the length of the wire, and A is the cross-sectional area of the wire.
We are given the cross-sectional area and resistivity of the wire, as well as the desired resistance. We can rearrange the formula above to solve for L as follows:
L = (RA)/ρ
Substituting the given values, we get:
L = (3 x 0.60 x 10^-6) / (7.2 x 10^-7) = 2.5 meters
Therefore, the length of wire that will have a resistance of 3Ω is 2.5m.
The correct option is (b) 2.50m.