A long metallic bar is carrying heat from one of its ends to the other end under steady-state. The variation of temperature `theta` along the length x of the bar from its hot end is best described by which of the following figures?

Options

A.
B.
C.
D.

Answer

B

Explanation

We know that
`(dQ)/(dt)= KA (d theta)/(dx)`
In steady state flow of heat
`d theta=(dQ)/(dt)xx(1)/(KA)xxdx`
`rArrtheta_(H)-theta=KxrArrtheta=theta_(H)-K_(x)`
The equation `theta =theta_(H) -Kx` represents a striaight line .