The resistivity of potentiometer wire is 40 × 10 - 8 Ω m and its area of cross-section is 8 × 10 - 6 m 2 . If 0 . 2 A current is flowing through the wire, the potential gradient of the wire is

Step-by-step solution

R = ρ l A ∴       R l = ρ A = 40 × 10 - 8 8 × 10 - 6 = 5 × 10 - 2 V l = I R l = 0.2 × 5 × 10 - 2 = 10 - 2   V   m - 1