High School Physics

# Temperature coefficient of resistance – formula

The temperature dependence of resistance of a conductor can be expressed with the formula R2 = R1 ( 1 + α t), where α is the temperature coefficient of resistance of the conductor. R2 and R1 represent the resistance of the conductor at t2° centigrade and t1° centigrade respectively. In the equation, t = temperature difference = (t2 – t1)

## Temperature coefficient of resistance formula

The formula to find out the Temperature coefficient of resistance of the conductor α = (R2R1) / (R1 t)

For metals, the value of the Temperature coefficient of resistance α is positive and lies between 10-2 to 10-4 °C-1.

## Temperature coefficient of resistance – Numerical problem solved

1 ) A metallic wire has a resistance of 3 Ω at 0°C and 4.8 Ω at 150°C. Find the Temperature coefficient of resistance.

Solution:

t = temperature difference = (t2 – t1) = 150 – 0 = 150°C.

R2 = 4.8 Ω

R1 = 3 Ω

Temperature coefficient of resistance α = (R2 – R1) / (R1 t) = (4.8-3) /(3x 150) = 0.004 °C-1

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