Light with an average flux of `20 W/cm^2` falls on a non-reflecting surface at normal incidence having surface area `20 cm^2`. The energy received by the surface during time span of 1 minute is:

Options

A. `10 xx 10^(3)J`
B. `12 xx 10^(3)` J
C. `24 xx 10^(3)J`
D. `48 xx 10^(3)` J

Answer

C

Explanation

Energy received= Intensity × Area × Time
`= (20)/(10^(-4)) xx 20 xx 10^(-4) xx 60= 24 xx 10^(3)` J