Two ends of a conducting rod of varying cross-section are maintained at `200^(@)C` and `0^(@)C` respectively. In steady state:

Options

A. Temperature difference across AB and CD are equal
B. Temperature difference across AB is greater than that of across CD
C. Temperature difference across AB is less than that of across CD
D. Temperature difference may be equal or different depending on the thermal conductivity of the rod

Answer

C

Explanation

Heat current will be same through every cross section
`H=(KADeltatheta)/(l)orDeltatheta=(Hl)/(KA)`
`(Deltatheta_(1))/(Deltatheta_(2))=((HX)/(KA_(1)))//(HX)/(KA_(2))=(A_(2))/(A_(1))`
Temperature difference will be more for lesser cross section