JEE Main 20146 April
- Exam
- JEE Main
- Year
- 2014
- Date
- 6 April
- Subject
- Physics
- Chapter
- Wave Optics
JEE Main 2014 · 6 April · Physics · Wave Optics
Two beams, A and B of plane polarized light with mutually...
Two beams, A and B of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of polaroid through 30o makes the two beams appear equally bright. If the initial intensities of the two beams are IA and IB respectively, then equals :
Options
- A3
- B
- C1
- D
Correct answer
D.
Step-by-step solution
{\text{I}}_{\text{A}} {\text\cos}^{2} \theta = {\text{I}}_{\text{B}} {\text\cos}^{2}\left(9 0 - \theta\right)\left(\text{I} = {\text{I}}_{0} {\text\cos}^{2} \theta\right) by malus equation
∴ \dfrac{{\text{I}}_{\text{A}}}{{\text{I}}_{\text{B}}} = {\text\tan}^{2} \theta = \dfrac{1}{3}
where
∴ \dfrac{{\text{I}}_{\text{A}}}{{\text{I}}_{\text{B}}} = {\text\tan}^{2} \theta = \dfrac{1}{3}
where