Question

a wire has resistance of 3.1 ohm at 30 degree Celsius and 4.5 ohm at 100 degree celsius. The temperature coefficient of resistance to the wire is approximately?​

Answer 1

Answer:

A wire has resistance of 3.1 ohm at 30 degree Celsius and 4.5 ohm at 100 degree celsius.

Thus,

R1 = 3.1 ohm at t = 30°C

R2 = 4.5 ohm at t = 100°C

We have, R = R0 (1+αt)

So, R1 = R0 (1+α * 30)

R2 = R0 (1+α * 100)

R1 / R2 = [(1+30α) / (1+100α)]

3.1 /4.5 = [(1+30α) / (1+100α)]  

Solving the above expression gives:

Temp. coefficient, α = 0.0085 0C-1