The graph, shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity and absorptivity power of the two bodies

Options

A. `e_(x) gt e_(y) and a_(x) lt a_(y)`
B. `e_(x) lt e_(y) and a_(x) gt a_(y)`
C. `e_(x) gt e_(y) and a_(x) gt a_(y)`
D. `e_(x) lt e_(y) and a_(x) lt a_(y)`

Answer

C

Explanation

Rate of cooling `(-(dT)/(dT)) prop` emissivith (e)
From graph, `(-(dT)/(dt))_(x) gt (-(dT)/(dt))_(y) rArr e_(x)gte_(y)`
Further emissivity (e) `prop` Absorpitive power (a)
`rArr a_(x) gta_(y)`
(`:'` good absorbers are good emitters).