Question

A wire has resistance 100 Ohm at 0 oC and 200 Ohm at 100 oC. What is its temperature coefficient in K-1?

Answer 1

Answer :

Resistance at 0°C = 100Ω

Resistance at 100°C = 200Ω

We have to find temperature coefficient of wire in Kˉ¹$.$

_________________________________

◈ Resistance of conductor depends on the length of conductor, area of cross-section of conductor and temperature.

Formula :

• ΔR = R × α × ΔT

ΔR denotes change in resistance

R denotes initial resistance

α denotes temperature coefficient

ΔT denotes change in temperature

✠ Initial temperature = 0°C = 273K

✠ Final temperatute = 100°C = 373K

⇒ ΔR = R × α × ΔT

⇒ (R₂ - R₁) = R₁ × α × (T₂ - T₁)

⇒ (200-100) = 100 × α × (373-273)

⇒ 100 = 100 × α × 100

⇒ α = 1/100

⇒ α = 1 × 10ˉ² Kˉ¹