Correct Answer - A::B::C::D
`H_1 + H_2 = 25`
`:. (theta -100)/(0.5//(400 xx 10^-4)) + (theta - 0)/(0.5 //(400 xx 10^-4)) = 25`
Solving this equation, we get
`theta ~~ 206^@C`
Now, temperature gradient on
`LHS = ((theta-100)/0.5) = 212^@C//m`
and on `RHS = (theta -0)/0.5 = 424 ^@C//m`.