Two metal rods made up of iron `(K_1=79Wm^(-1)K^(-1))` and brass `(K_2=109Wm^(-1)K^(-1))` are of identical shape and size. These are fused at the junction. If the temperature at the free end of iron is at a steam point and brass at ice point then calculate the temperature at the junction, when the steady state is attained.

Explanation

Since `Q_1=Q_2,A_1=A_2,L_1=L_2,t_1=t_2`
`K_1(theta_1-theta)=K_2(theta-theta_2)`
i.e, `79(373-theta)=109(theta-29757)`
`29467-79theta=109theta-29757`
i.e. `188theta=59224`
`:.theta=315.0K`
Hence the temperature of the junction is 315K