Consider a beam of light of power 7.2 W incident on a prism of angle `0.9^(@), lambda=221` nm.

Options

A. The angle of deviation is `(pi)/(400)` rad
B. The number of photons incident on the prism/time is `8xx10^(18)`/sec
C. The magnitude of component of force on prism in y direction is approx `6pixx10^(-10)N`
D. There is a component of force on prism in-ve y-direction.

Answer

A, B

Explanation

`delta=(mu-1)A=(1.5-1)xx(0.9pi)/(180)=(pi)/(400)"rad". `
`(dN)/(dt)=(rho)/((hc)/(lambda))=(7.2xx221xx10^(-9))/(6.63xx10^(-34)xx3xx10^(8))=8xx10^(18)//"sec".`
`Deltap_(y)=(dN)/(dt)xx(h)/(lambda)sin delta`
`=8xx10^(18)xx(6.63xx10^(-34))/(221xx10^(-9))xx(pi)/(400)=6pixx10^(-11)N`