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Multiple choice polarisation of light polarisation wave optics optics physics

Bartholinus discovered :

  1. Interference by splitting the wave front

  2. Polarisation by reflection

  3. Polarisation by refraction

  4. Polarisation by double refraction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In 1669, another Danish scientist, Erasmus Bartholinus discovered the polarization of light by double refraction in Iceland spar (calcite).

Multiple choice polarisation of light polarisation wave optics optics physics

Choose the correct statements among the following given options.

  1. Brewster's angle is independent of wavelength of light.

  2. Brewster's angle is independent of the nature of reflecting surface.

  3. Brewster's angle is different for different wavelengths.

  4. Brewsters angle depends on wavelength but not on the nature of reflecting surface.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Brewster's angle is an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface,
with no reflection.
$\theta _{B}=tan^{-1}(\dfrac{n _{2}}{n _{1}})$
$n _{2}$ refractive index of final medium
$n _{1}$ refractive index of initial medium
As different wavelength have different refractive indices the brewster angle is also different.

Multiple choice polarisation of light polarisation wave optics optics physics

Pile of plates can be used to produce completely polarised light due to :

  1. Reflection

  2. Refraction

  3. Double refraction

  4. A and B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

pile of plates is used to produce plane polarized light by refraction.
By refraction through multiple plates vibrations in the plane of incidence are transmitted.
Thus we obtain a polarized light.

Multiple choice polarisation of light polarisation wave optics optics physics

At the polarising angle $(\theta _{B})$, angle of refraction is given by : 

  1. $90^{\circ}$

  2. $90^o+\theta _{B}$

  3. $90^o-\theta _{B}$

  4. $\dfrac{90^o}{\theta _B }$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

At polarizing angle $\theta _{B}$
$\dfrac{sin \theta _{B}}{cos \theta _{B}}=\dfrac{sin \theta _{B}}{sin \gamma }$
we get $sin \gamma =cos \theta _{B}$
$sin \gamma =sin(90-\theta _{B})$
Thus $\gamma =90-\theta _{B}$

Multiple choice polarisation of light polarisation wave optics optics physics

The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index n) is :

  1. $sin^{-1}(n)$

  2. $sin^{-1}(1/n)$

  3. $ tan^{-1}(n)$

  4. $ tan^{-1}(1/n)$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The refractive index of glass is n
If the light is incident on the surface with an angle of incidence i given by tan i $=\mu $ using the Brewster's law the reflected light is completely polarized.
Here tan i $=n$
i$=tan^{-1}(n)$

Multiple choice polarisation of light polarisation wave optics optics physics

A light ray is incident on a transparent medium of $\mu =$ 1.732 at the polarizing angle. The angle of refraction is :

  1. 60$^{\circ}$

  2. 30$^{\circ}$

  3. 45$^{\circ}$

  4. 90$^{\circ}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Angle of incidence $=$ polarising angle
$tan i = \mu $
$tan i = 1.732$
$i = 60^{0}$
From snell's law
$\dfrac{sin i}{sin \gamma }=\mu $
$sin \gamma =\dfrac{sin 60^{0}}{1.732}$
$\gamma =30^{0}$

Multiple choice polarisation of light polarisation wave optics optics physics

The critical angle for total internal reflection for a substance is $45^{\circ}$. The polarizing angle for this substance is ($\tan 54^{\circ}44'=\sqrt{2}$) :

  1. $46^{\circ}16'$

  2. $54^{\circ}44'$

  3. $46^{\circ}44'$

  4. $54^{\circ}16'$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If polarizing angle is $\theta $
Then tan $\theta =\dfrac{1}{sin c}$
$tan \theta =\dfrac{1}{sin 45}=\sqrt{2}$
$\theta =54^{0}{44}'$

Multiple choice polarisation of light polarisation wave optics optics physics

ASSERTION (A):Hyugens' theory failed to explain polarization
REASON (R): According to Hyugens' theory light is longitudinal wave

  1. A is correct, R is correct and it is the correct explanation

  2. A is correct, R is correct but it is not a correct explanation

  3. A is correct, R is wrong

  4. A is wrong , R is correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Huygen's theory failed to explain polarisation because according to the Huygen's theory light is a longitudinal waves and longitudinal wave does not shows polarisation.

Multiple choice polarisation of light polarisation wave optics optics physics

According to Maxwell , most of the optical properties of light depend on

  1. Magnetic vector

  2. Electric vector

  3. Both Electric and Magnetic vectors

  4. Can not be decided
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The experiments on stationary light waves establish that most of the optical properties of light depends on the electric vector, which is also known as light vector.

Multiple choice polarisation of light polarisation wave optics optics physics

Identify which of the following should be used for polarised light waves?
I. Sunglasses
II. Remove ultraviolet light
III. Reveal stress patterns

  1. I only

  2. II only

  3. I and III only

  4. II and III only

  5. I, II, and III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Polarizers are used in industry to reveal stress patterns in machinery and tools. Sunglasses are used to protect the eyes by polarizing the light to reduce glare using the tailor-made material of the glasses.