One end of a conducting rod is maintained a temperature `50^(@)C` and at the other end ice is melting at `0^(@)C`. The rate of melting of ice is doubled if

Options

A. The temperature is made 200°C and the area of cross-section of the rod is doubled
B. The temperature is made 100°C and length of the rod is made four times
C. Area of cross-section of rod is halved and length is doubled
D. The temperature is made 100°C and area of cross-section of rod and length both are doubled

Answer

D

Explanation

`H=(KADeltaT)/(l)=(KA(50))/(l)` In option (D) `H'=(k(2A)100)/(k(2l))=(2xxKA(50))/(l)`