Question

a piece of platinum wire has a resistance of 2.5 ohm at 0 °c if the temperature coefficient of resistance is 4×10^ 3 °c find the resistance of the wire at 80 degrees celsius​

Answer 1

Answer : The Resistance of wire at 80° celsius is 3.3 ohm.

Explanation:

Given : Ro = 2.5 ohm

α = 4 × 10^3 °c = 0.004/ °c

T = 80 °c

To find : Resistance at 80°c ( Rt )

Formula : Rt = Ro ( 1 + αT )

Substituting the given value in above formulas

∴ Rt = 2.5 ( 1 + 0.004 × 80 )

∴ = 2.5 ( 1 + 0.32 )

∴ = 2.5 × 1.32

∴ Rt = 3.3 ohm