Two rods whose lengths are `l_1` and `l_2`  and heat conductivity coefficient `x_1` and `x_2` are pl
Channel: Doubtnut
Date: 2020-08-16

Two rods whose lengths are `l_1` and `l_2`  and heat conductivity coefficient `x_1` and `x_2` are placed end to end. Find the heat conductivity coefficient of a uniform rod of length `l_1 + l_2` whose conductivity is the same as that of the system of these two rods. The lateral surfaces of the rods are assumed to be thermally insulated.