CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
0
You visited us 0 times! Enjoying our articles? Unlock Full Access!
Question

A sphere of radius 1.00 cm is placed in the path of a parallel beam of light of large aperture. The intensity of the light is 0.50 W/cm2. If the sphere partially absorbs (α=0.25) the radiation falling on it, find the force exerted by the light beam on the sphere.

A
5.2×107 N
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
9.16×109 N
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
8.5×107 N
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
9.3×107 N
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 9.16×109 N
Force=IAc(1+r)=πr2Ic(1+r)

Given, I=0.5 W/cm2=5000 W/m2
r=1 cm=102 m, c=3×108 m/s
α=0.25r=1α=10.25=0.75

F=π×(102)2×50003×108×(1+0.75)

F=9.16×109 N

Hence, (C) is the correct answer.
Why this question?

Caution: If α is given in the question, we can use the formula,

Force=IA(2α)c

Else, calculate, r=1α for using the formula used in solution.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Hooke's Law
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon