Two rods `A` and `B` are of equal lengths. Their ends of kept between the same temperature and their area of cross-section are `A_(1)` and `A_(2)` and thermal conductivities `K_(1)` and `K_(2)`. The rate of heat transmission in the two rods will be equal, if

Options

A. `K_(1) A_(2) = K_(2) A_(1)`
B. `K_(1) A_(1) = K_(2) A_(2)`
C. `K_(1) = K_(2)`
D. `K_(1) A_(1) = K_(2) A_(2)`

Answer

B

Explanation

(2) `i = (theta_(1) - theta_(2))/(R )`
`R_(A) = R_(B)`
`(l)/(K_(1) A_(1)) = (l)/(K_(2) A_(2)) implies K_(1) A_(1) = K_(2) A_(2)`