Tag: wave optics

Questions Related to wave optics

A polariser is used to :

polarisation of light polarisation wave optics optics physics

  1. Reduced intensity of light

  2. Produced polarised light

  3. Increases intensity of light

  4. Produced unpolarised light

Show answer
Correct Option: B

Which inert gas possesses the highest polarizability ? 

polarisation of light polarisation wave optics optics physics

  1. He

  2. Ne

  3. Ar

  4. Xe

Show answer
Correct Option: D

Two liner polarizers are crossed at an angle of ${ 60 }^{ \circ  }$. The fraction of intensity of light transmitted by the pair is

polarisation of light polarisation wave optics optics physics

  1. $\dfrac { 1 }{ 4 } $

  2. $\dfrac { 1 }{ 8 } $

  3. $\dfrac { 3 }{ 8 } $

  4. $\dfrac { 1 }{ 2 } $

Show answer
Correct Option: A

A polaroid making an angle ${ 60 }^{ \circ  }$ with electric vector then intensity reduced by a factor of:-

polarisation of light polarisation wave optics optics physics

  1. $\dfrac { 1 }{ 4 } $

  2. $\dfrac { 3}{ 4 } $

  3. $\dfrac { 1 }{ 2 } $

  4. $\dfrac { 1 }{ 3} $

Show answer
Correct Option: A

Two polaroids are placed in the path of unpolarized beam of intensity ${ I } _{ 0 }$ such that no light is emitted from the second polaroid. if  a third polaroid whose polarization axis makes an angle $\theta $ with the polarization axis of first polaroid is plcaed between these polaroids then the intensity of light emerging from the last polaroid is 

polarisation of light polarisation wave optics optics physics

  1. $\left( \frac { { I } _{ 0 } }{ 8 } \right) { sin }^{ 2 }2\theta $

  2. $\left( \frac { { I } _{ 0 } }{ 4 } \right) { sin }^{ 2 }2\theta $

  3. $\left( \frac { { I } _{ 0 } }{ 4 } \right) { cos }^{ 4 }\theta $

  4. ${ I } _{ 0 }{ Cos }^{ 4 }\theta $

Show answer
Correct Option: A

Two polaroids are placed in the path of unpolarized beam of intensity $I _ { 0 }$ such that no light is emitted from the second Polaroid. If a third Polaroid whose polarization axis makes an angle $\theta$ with the polarization axis of first polaroid, is placed between these polaroids then the intensity of light emerging from the last polarids will be :

polarisation of light polarisation wave optics optics physics

  1. $\left( \dfrac { I _ { 0 } } { 8 } \right) \sin ^ { 2 } 2 \theta$

  2. $\left( \dfrac { I _ { 0 } } { 4 } \right) \sin ^ { 2 } 2 \theta$

  3. $\left( \dfrac { I _ { 0 } } { 2 } \right) \cos ^ { 4 } \theta$

  4. $I _ { 0 } \cos ^ { 4 } \theta$

Show answer
Correct Option: A

Which of the following is not an anisotropic?

polarisation of light polarisation wave optics optics physics

  1. zinc blend

  2. quartz

  3. sapphire

  4. iron oxide

  5. apatite

Show answer
Correct Option: A
Explanation:
Anisotropy is the property of being directionally dependent, which implies different properties in different directions.
Zinc blend (ZnS) is the only isotropic material in the list.
Quartz crystals and Saphire are birefringent, so they exhibit optical anisotropy.

The extraordinary waves in Iceland's spar

polarisation of light polarisation wave optics optics physics

  1. travel faster than speed of light

  2. travel slower than speed of light

  3. wave fronts follow laws of refraction.

  4. only ellipsoidal wave fronts observe laws of refraction

Show answer
Correct Option: D

A calcite crystal is placed over a dot on a piece of paper and rotated. On viewing through calcite, one will see

polarisation of light polarisation wave optics optics physics

  1. a single dot.

  2. two stationary dots.

  3. two rotating dots.

  4. one dot rotating about the other.

Show answer
Correct Option: D
Explanation:

A dot which is shifted by some distance is appeared due to normal incidence and another dot is appeared which is rotating along with the crystal, when we see at a angle to the normal.
Hence option $D$ is correct .

Optically active substances are those which

polarisation of light polarisation wave optics optics physics

  1. produces polarized light

  2. rotate the plane of polarization of polarized light

  3. produce double refraction

  4. convert the plane polarized light into circularly polarized light

Show answer
Correct Option: B
Explanation:

The ability of a substance to rotate plane-polarized light is called optical activity and these substances are called optically active