Brewster's Angle

Q. The path difference between two interfering waves at a point on the screen is λ /6 from central maximum. The ratio of intensity at this point and that at the central fringe will be

Q.

When light is incident at the polarizing angle, which is completely polarized?

1. Reflected light

2. Refracted light

3. both

4. neither

Q. An unpolarised light is incident upon a glass plate of refractive index 1.54 at Brewster’s angle and gets completely plane polarized. The angle of polarization is: $(giventan{57}^{\circ }=1.54$)

1. ${57}^{\circ }$
2. ${46}^{\circ }$
3. ${33}^{\circ }$
4. ${82}^{\circ }$

Q. The velocity of light in air is $3\times {10}^8$ m/s and in a medium is $\sqrt{3}\times {10}^8$ m/s. The Brewster’s angle of the medium is

1. ${30}^{\circ }$
2. ${60}^{\circ }$
3. ${45}^{\circ }$
4. ${90}^{\circ }$

Q. The velocity of light in air is $3\times {10}^8$ m/s and in a medium is $\sqrt{3}\times {10}^8$ m/s. The Brewster’s angle of the medium is

1. ${30}^{\circ }$
2. ${60}^{\circ }$
3. ${45}^{\circ }$
4. ${90}^{\circ }$

Q. A beam of unpolarized light is passed first through a tourmaline crystal $A$ and then through another tourmaline crystal $B$ , oriented so that its principal plane is parallel to that of $A$. The intensity of the emergent light is $I$. The crystal $A$ is now rotated by ${45}^{\circ }$ in a plane perpendicular to the direction of the incident ray. Find the ratio of the final intensity of the emergent light, in the second case, to that in the first case.

1. $\frac{1}{\sqrt{2}}$
2. $\frac{1}{2}$
3. $1$
4. $\frac{1}{4}$