Question

The resistance of a nichrome wire at 0 °C is 10 Ω. If its temperature coefficient of resistance is 0.004/°C, find its resistance at boiling point of water. Comment on the result.

Answer 1

Resistance of a nichrome wire at 0°C, R₀ = 10 Ω Temperature co-efficient of resistance, 

α = 0.004/°C

Resistance at boiling point of water, RT = ? 

Temperature of boiling point of water, T = 100 °C

R_T =R₀ ( 1 + αT) = 10[1 + (0.004 x 100)]

R_T = 10(1 +0.4) 

= 10 x 1.4 R = 14 Ω

As the temperature increases the resistance of the wire also increases.