Question

A wire has resistance of 3.1 2 at 30°C and
resistance 4.5 22 at 100°C. The temperature
coefficient of resistance of the wire is :
(a) 0.0012° 0-1
(b) 0.0024°C-1
(c) 0.0032° 0-1
(d) 0.0064°C-1​

Answer 1

Answer:

0.0012°

is the answer...

Answer 2

Explanation:

Given : RT=3.1 ohm @ T=30oC

Also, RT′=4.5 ohm @ T′=100oC

Resistance of wire at any temperature RT′=RT[1+α(T′−T)]

∴ 4.5=3.1[1+α(100−30)]

$= > \alpha = \frac{0.45}{70}$

=0.0064oC−1