Question

A 5C rise in temperature is observed in a conductor by passing a current through it ,when the current is doubled, the rise in temperature is​

Answer 1

Joule heat produced in the conductor is

I^2Rt=H.

I is current, R is resistance of the conductor , t is time.

If we assume that this heat is completely used in increasing temperature of the conductor in time t,then

H=ms(theta), where m is mass of the conductor, s is specific heat of the material of the conductor and (theta) is increase in temperate.

Again assuming that during increase in temperature in the present case, the resistance does not change ,then

(Theta) is proportional to I^2.

Now, (theta)/5=(2I/I)^2=4. Therefore ,

(theta)=20 degree.