A slab `X` of thickness `'t'`, thermal conductivity `'K'` and area of cross-section `'A'` is placed in thermal contact with another slab `Y` which is `2n^(2)` times thicker, `4n` times conductive and having `n` times larger cross-section area. If the outside face of `X` is maintained at `100^(@)C`, the outside face of `Y` at `0^(@)C`, then the temperature of the junction is represented by the graph `(ngt0)`

Options

A.
B.
C.
D.

Answer

A

Explanation

At equilibrium : `Q_(1)=Q_(2)`
`implies(KA(t-0))/l=(4nk An (100-5))/(2n^(2)l)`
`=t=200//3`