Question

At what temperature would tje resistence of a copper conductor be double its resistence at 0c (given alpha for copper = 3.9 ×10^-3

Answer 1

From the resistance variation with temperature equation , we know

R = R₀(1+αt)

where,

R = resistance at temperature t

R₀ = resistance at 0°c

From the given question R/R₀ = 2

=> 2 = 1+αt

=> αt = 1

=> t = 1/α = 1/3.9 x10⁻³ = 256° C

Hence the temp at which the resistance of copper will become double its resistance at 0°c is 256°C

Answer 2

Given:

α = 3.9 * 10^-3

To find:

The resistance of a copper conductor be double its resistance.

Solution:

By formula,

Resistance ( t ) = Resistance ( 0 ) ( 1 + α t )

Where,

t - temperature t

0 - 0 degree

Hence,

Resistance ( t ) = 2 * Resistance ( 0 )

So,

We get,

2 = 1 + α t

Substituting,

α t = 1

t = 1 / α

1 / 3.9 * 10⁻³

256 degree

Hence, at 256 degrees, the temp at which the resistance of copper will become double its resistance at 0 degree.