Consider a light beam incident from air to a glass slab at Brewster’s angle as shown in figure. A polaroid is placed in the path of the emergent ray at point P and rotated about an axis passing through the centre and perpendicular to the plane of the polaroid.
Consider a light beam incident from air to a glass slab at Brewster’s angle as shown in figure. A polaroid is placed in the path of the emergent ray at point P and rotated about an axis passing through the centre and perpendicular to the plane of the polaroid.
The correct option is C The intensity of light as seen through the Polaroid shall go through a minimum but not zero for two orientations of the polaroid.
Definition: Brewster’s law: When an unpolarized light of known wavelength is incident on a transparent substance surface, it experiences maximum plan polarization at the angle of incidence whose tangent is the refractive index of the substance for the wavelength.
As given the angle of incidence of unpolarized light is equal to Brewster’s angle, therefore polarization of reflected ray will happen, but emergent ray will still be unpolarised in nature.
Therefore, there will no particular orientation such that there shall be complete darkness while observing through polaroid. But still, the intensity of light will be dependent on the rotation of Polaroid, as the light ray which will be parallel to the axis of Polaroid will be able to pass through it. Therefore, at a particular angle, the intensity of light will go minimum but not zero.
Final answer: (C)
The intensity of light as seen through the Polaroid shall go through a minimum but not zero for two orientations of the polaroid.
Definition: Brewster’s law: When an unpolarized light of known wavelength is incident on a transparent substance surface, it experiences maximum plan polarization at the angle of incidence whose tangent is the refractive index of the substance for the wavelength.
As given the angle of incidence of unpolarized light is equal to Brewster’s angle, therefore polarization of reflected ray will happen, but emergent ray will still be unpolarised in nature.
Therefore, there will no particular orientation such that there shall be complete darkness while observing through polaroid. But still, the intensity of light will be dependent on the rotation of Polaroid, as the light ray which will be parallel to the axis of Polaroid will be able to pass through it. Therefore, at a particular angle, the intensity of light will go minimum but not zero.
Final answer: (C)
