Three rods of copper, brass and steel are welded together to form a Y -shaped structure. The cross-sectional area of each rod is `4 cm^2`. The end of copper rod is maintained at `100^@C` and the ends of the brass and steel rods at `80^@C` and `60^@C` respectively. Assume that there is no loss of heat from the surfaces of the rods. The lengths of rods are : copper 46 cm, brass 13 cm and steel 12 cm.
(a) What is the temperature of the junction point?
(b) What is the heat current in the copper rod?
K(copper) = 0.92, K (steel) = 0.12 and K(brass) = 0.26 `cal//cm.s^@C` .

Explanation

`i=i_(i)+i_(2)`
`=(0.96xx4xx(10-theta))/(48)=(0.28xx4(theta-0))/(14)+(0.12xx4xx(theta-0))/(12)`
`0.02(10-theta)=0.02theta+0.019`
`theta=4^(@)C`