Two beams, A and B, of plane polarised light with mutually
perpendicular planes of polarisation 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 30$^{\circ}$ makes the two beams appear equally
bright. If the initial intensities of the two beams are $I_A \, and \, I_B$ respectively, then $I_A / I_B$ equals
- 3
- 44622
- 1
- 44564
The Correct Option is D
Solution and Explanation
Top Questions on Polarisation
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Let \( ABC \) be a triangle. Consider four points \( p_1, p_2, p_3, p_4 \) on the side \( AB \), five points \( p_5, p_6, p_7, p_8, p_9 \) on the side \( BC \), and four points \( p_{10}, p_{11}, p_{12}, p_{13} \) on the side \( AC \). None of these points is a vertex of the triangle \( ABC \). Then the total number of pentagons that can be formed by taking all the vertices from the points \( p_1, p_2, \ldots, p_{13} \) is ___________.
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Concepts Used:
Polarisation
Light travels in form of transverse EM waves. The underlying oscillation is along directions perpendicular to the propagation direction, in this example, oscillating electric and magnetic fields. Process of restricting the vibration of light waves to one direction is known as Polarisation.
Types of Polarisation:
There are three types of polarisation such as:
- Linear Polarisation in the electric field of light is limited to one single plane that is along the direction of propagation.
- Elliptical Polarisation: In this, both the phase difference and amplitude between the two linear components are not equal.
- Circular Polarisation: The electric field of light follows a circular propagation. The two linear components that exist in the electric field are the same amplitudes but have different phase differences.
Methods of Polarisation of Light:
The few methods of polarisation of Light are:
- Polarization by dispersing
- Polarization by Reflection
- Polarization by Refraction
- Polarization By Transfer