Question

The resistance of a conducting wire at a temperature of 27oc is found to be 1. If the temperature coefficient of the wire is given to be (1.25 10-3)c-1, at what temperature will the resistance of the wire be 2?

Answer 1

Answer:

1100K

Explanation:

Initial temperature of the wire = 27°C (Given)

Initial resistance of the wire = 1 (Given)

Temperature coefficient of the wire = (1.25 10-3)c-1 (Given)

Resistance of wire is a linear function of temperature.

Therefore,

α = ΔR / (RΔθ)

Δθ = ΔR / (Rα)

(T - 27) = (2 Ω - 1 Ω) / (1 Ω × 0.00125 /°C)

T - 27 °C = 800 °C

T = 27 °C + 800°C

T = 827 °C

T = (827 + 273) K

T = 1100 K

Thus, the temperature of the wire will be 1100 K.