Q29.A source of light is placed in front of a screen. The intensity of light on the screen is I . Two Polaroids P1 and P2 are so placed in between the source of light and screen that the intensity of light on the screen is I2 . Then the P2 , should be rotated by an angle of (degrees) so that the intensity of light on the screen becomes 3I8 .
What This Question Tests
This question applies Malus's Law twice to determine the required angle of rotation of a polaroid to achieve a specific intensity of transmitted light.
Concepts Tested
Formulas Used
I = I₀cos²θ
📚 NCERT Sections This Tests
10.5 — In Young’S Double-Slit Experiment Using Monochromatic Light Of
Physics Class 12 · Chapter 10
10.5 In Young’s double-slit experiment using monochromatic light of wavelength l, the intensity of light at a point on the screen where path difference is l, is K units. What is the intensity of light at a point where path difference is l/3?
9.21 — At What Angle Should A Ray Of Light Be Incident On The Face Of A Prism
Physics Class 12 · Chapter 9
9.21 At what angle should a ray of light be incident on the face of a prism of refracting angle 60° so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is 1.524.
10.4 — In A Young’S Double-Slit Experiment, The Slits Are Separated By
Physics Class 12 · Chapter 10
10.4 In a Young’s double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment.
📋 Question Details
- Chapter
- Wave Optics
- Topic
- Polarization
- Year
- 2021
- Shift
- 26 Aug Shift 2
- Q Number
- Q29
- Type
- Numerical
- NCERT Ref
- Class 12 Physics Ch 10: Wave Optics
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