wiz-icon
MyQuestionIcon
MyQuestionIcon
4
You visited us 4 times! Enjoying our articles? Unlock Full Access!
Question

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is π2 at point A and 2π at point B. Then the difference between the resultant intensities at B and A will be

A
4I
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
3I
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
I
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
5I
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 4I
Resultant amplitude of interference
A=A21+A22+2A1A2cosϕ
Intensity IA2
resultant intensity is given by
If=I1+I2+2I1I2cosϕ
where ϕ is the phase difference between the two waves at the point.
At point A,
IA=I+4I+2I×4I×cosπ2
=5I
At point B,
IA=I+4I+2I×4I×cos2π
=9I

IBIA=4I

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon