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Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice polarisation of light polarisation wave optics optics physics

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

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

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

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

  4. $\dfrac { 1 }{ 3} $
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If a polarizer makes an angle of 60 degrees with the electric vector of polarized light, the intensity is reduced by a factor of cos^2(60) = (1/2)^2 = 1/4.

Multiple choice polarisation of light polarisation wave optics optics physics

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 

  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 $
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The derivation is identical to question 527898. The intensity is (I0/8) * sin^2(2*theta).

Multiple choice polarisation of light polarisation wave optics optics physics

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 :

  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. $I _ { 0 } \cos ^ { 4 } \theta$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is a repeat of the previous question. The intensity is (I0/8) * sin^2(2*theta).

Multiple choice polarisation of light polarisation wave optics optics physics

Which of the following is not an anisotropic?

  1. zinc blend

  2. quartz

  3. sapphire

  4. iron oxide

  5. apatite
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice polarisation of light polarisation wave optics optics physics

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

  1. a single dot.

  2. two stationary dots.

  3. two rotating dots.

  4. one dot rotating about the other.
Reveal answer Fill a bubble to check yourself
D Correct answer
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 .

Multiple choice polarisation of light polarisation wave optics optics physics

Optically active substances are those which

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

Multiple choice polarisation of light polarisation wave optics optics physics

Light transmitted in Nicol prism is

  1. unpolarized

  2. plane polarized

  3. circularly polarized

  4. elliptically polarized
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In Nicol Prism, ordinary ray is eliminated and Extra-ordinary ray, which is plane polarized, is transmitted through the prism.

Multiple choice polarisation of light polarisation wave optics optics physics

In, the case of linearly polarized light the magnitude of electric field vector

  1. vary periodically with time

  2. increases and decreases linearly with time

  3. does not change with time

  4. is parallels to the direction of propagation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In general equation for electric field vector for linearly polarized light is given as $\left| \vec { E }  \right| ={ E } _{ o }\sin { \left( { \omega t }-{ kx } \right)  } $ which indicate that its varies periodically with respect to time.

Such that it is perpendicular to the direction of propagation

Multiple choice polarisation of light polarisation wave optics optics physics

Two beams, A and B of plane polartice light with mu;a;y perpendicular plances of po;arixation are seen triugh  polaroid from the position wjen the beam B has xero intensity a rotation of polato thorough 30 makes the two beams appear equally bright if the intial  Intensites of the two beams are 1 and 1 rtespctively the n equls 

  1. 3

  2. $\frac { 3 }{ 2 } $

  3. 1

  4. $\frac { 1 }{ 3 } $
Reveal answer Fill a bubble to check yourself
A Correct answer