MEDIUM

Earn 100

What is Birefringence?

Important Questions on Wave Optics

EASY

The polarising angle for transparent medium is

θ

v

is the speed of light in that medium. Then the relation between

θ

and

v

is (

c

= velocity of light in air)

EASY

Physics>Optics>Wave Optics>Polarisation

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 30^o makes the two beams appear equally bright. If the initial intensities of the two beams are I_A and I_B respectively, then

\frac{I_{A}}{I_{B}}

equals :

HARD

Physics>Optics>Wave Optics>Polarisation

Unpolarized light of intensity

I

is incident on a system of two polarizers,

A

followed by

B

. The intensity of emergent light is

\frac{I}{2}

. If a third the polarizer

C

is placed between

A

and

B

the intensity of emergent light is reduced to

\frac{I}{3}

. The angle between the polarizers

A

and

C

θ

, then

MEDIUM

Physics>Optics>Wave Optics>Polarisation

A system of three polarizers

P_{1}, P_{2}, P_{3}

is set up such that the pass axis of

P_{3}

is crossed with respect to that of

P_{1}

. The pass axis of

P_{2}

is inclined at

60^{o}

to the pass axis of

P_{3} .

When a beam of unpolarized light of intensity

I_{o}

is incident on

P_{1},

the intensity of light transmitted by the three polarizers is

I

. The ratio

(I_{o} / I)

equals (nearly):

MEDIUM

Physics>Optics>Wave Optics>Polarisation

Write definitions of plane of vibration and plane of polarisation.

Explain the working process to obtain plane polarised light by Nicol Prism.

Draw necessary diagram.

EASY

Physics>Optics>Wave Optics>Polarisation

Unpolarized light of intensity

I

passes through an ideal polariser

A

. Another identical polariser

B

is placed behind

A

. The intensity of light beyond B is found to be

\frac{I}{2}

. Now another identical polariser

C

is placed between

A

and

B

. The intensity beyond B is now found to be

\frac{I}{8}

. The angle between polariser

A

and

C

MEDIUM

Physics>Optics>Wave Optics>Polarisation

Two circular linear polarisers are placed coaxially. The transmission axis of the first polariser is

30 °

from the vertical while the second one is at

60 °

, both in the clockwise sense. If an unpolarised beam of light of intensity,

I = 20 W m^{- 2}

is incident on this pair of polarisers, then the intensities

I_{1}

and

I_{2}

transmitted by the first and the second polarisers, respectively, will be close to,

EASY

Physics>Optics>Wave Optics>Polarisation

Three polaroid sheets

P_{1}, P_{2}

and

P_{3}

are kept parallel to each other such that the angle between pass axes of

P_{1}

and

P_{2}

45 °

and that between

P_{2}

and

P_{3}

45 °

. If unpolarised beam of light of intensity

128 W m^{- 2}

is incident on

P_{1}

. What is the intensity of light coming out of

P_{3}

MEDIUM

Physics>Optics>Wave Optics>Polarisation

Explain polarisation by scattering.

MEDIUM

Physics>Optics>Wave Optics>Polarisation

A beam of unpolarised light of intensity

I_{0}

is passed through a polaroid

A

and then through another polaroid

B

which is oriented so that its principle plane makes an angle of

45^{o}

relative to that of

A

. The intensity of the emergent light is:

HARD

Physics>Optics>Wave Optics>Polarisation

A polarizer - analyser set is adjusted such that the intensity of light coming out of the analyser is just

10 %

of the original intensity. Assuming that the polarizer - analyser set does not absorb any light, the angle by which the analyser needs to be rotated further, to reduce the output intensity to zero, is

EASY

Physics>Optics>Wave Optics>Polarisation

When the angle of incidence on a transparent material is

60 °

, the reflected light is completely polarised. The velocity of refracted ray inside the material is

EASY

Physics>Optics>Wave Optics>Polarisation

A transparent medium shows relation $i$ and $r$ as shown. If the speed of light in vacuum is $c,$ the Brewster angle for the medium is

Question Image

MEDIUM

Physics>Optics>Wave Optics>Polarisation

Two Polaroids

P_{1}

and

P_{2}

are placed with their axis perpendicular to each other. Unpolarised light with intensity

I_{0}

is incident on

P_{1}

. A third polaroid

P_{3}

is kept in between

P_{1}

and

P_{2}

such that its axis makes an angle

45^{o}

with that of

P_{1}

. The intensity of transmitted light through

P_{2}

MEDIUM

Physics>Optics>Wave Optics>Polarisation

The Brewsters angle

i_{b}

for an interface should be

EASY

Physics>Optics>Wave Optics>Polarisation

A beam of light falls on a system of

4

polaroids, which are arranged in succession, such that the axis of each polaroids makes

30 °

with the axis of the preceding one. The fraction of the intensity of the incident light that passes through the system is

MEDIUM

Physics>Optics>Wave Optics>Polarisation

A ray of unpolarised light is incident on the glass surface of refractive index

1.73

at polarizing angle. The angle of refraction will be [Take

\tan 60 ° = 1.73

]

MEDIUM

Physics>Optics>Wave Optics>Polarisation

Unpolarized light of intensity

I_{0}

is incident on surface of a block of glass at Brewster's angle. In that case, which one of the following statements is true?

MEDIUM

Physics>Optics>Wave Optics>Polarisation

The Brewster's angle for air to water interface is

MEDIUM

Physics>Optics>Wave Optics>Polarisation

A beam of plane polarized light of large cross-sectional area and uniform intensity of

3 .3 W m^{- 2}

falls normally on a polarizer (cross-sectional area

3 \times 10^{- 4} m^{2}

), which rotates about its axis with an angular speed of

31 .4 rad s^{- 1}

. The energy of light passing through the polarizer per revolution, is close to:

What is Birefringence?

Important Questions on Wave Optics

Learn and Prepare for any exam you want !