Question

The resistance of a wire is 10 Ω at 27°C. Find its resistance at −73°C. The temperature coefficient of resistance of the material of the wire is 1.70 × 10⁻⁴°C⁻¹.

Answer 1

We can use the formula for the change in resistance due to temperature:

ΔR = R₀ α ΔT

ΔR = 1.70 × 10⁻⁴ Ω

Now, to find the resistance at −73°C, we add the change in resistance to the initial resistance:

R₋₇₃ = R₀ + ΔR

R₋₇₃ = 10 Ω + 1.70 × 10⁻⁴ Ω

R₋₇₃ = 10.00017 Ω

Therefore, the resistance of the wire at −73°C is approximately 10.00017 Ω.