Tag: wave optics

Quizzes (12) Questions (312)

Questions Related to wave optics

Multiple choice polarisation of light polarisation wave optics optics physics

Through which character we can distnguish the light waves from sound waves.

  1. Interference

  2. Refraction

  3. Polarisation

  4. Reflection
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both light and sound waves exhibit interference, refraction, and reflection because these are general wave properties. However, light is a transverse electromagnetic wave and can be polarized, whereas sound is a longitudinal pressure wave and cannot be polarized.

Multiple choice polarisation of light polarisation wave optics optics physics

In the propagation of light waves, the angle between the direction of vibration and plane of polarization is :

  1. $0^{ \circ }$
  2. $90^{ \circ }$
  3. $45^{ \circ }$
  4. $80^{ \circ }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In transverse wave propagation, the direction of vibration of the electric field vector is perpendicular to the direction of wave travel, while the plane of polarization contains the direction of propagation and the vibration vector. Thus, the angle between the direction of vibration and the plane of polarization is 90 degrees.

Multiple choice polarisation of light polarisation wave optics optics physics

A stretched string is 1 m long. Its mass per unit length is 0.5 g/m. It is stretched with a force of 20 N. It plucked at a distance of 25 cm from one end. The frequency of note emitted by it will be:

  1. $400 Hz$
  2. $300 Hz$
  3. $200 Hz$
  4. $100 Hz$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice polarisation of light polarisation wave optics optics physics

Which of the following cannot be polarised

  1. Radio waves

  2. UV rays

  3. IR rays

  4. Ultrasonic waves
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Polarization is a property of transverse waves. Ultrasonic waves are longitudinal waves and cannot be polarized.

Multiple choice polarisation of light polarisation wave optics optics physics

A beam of light strikes a piece of glass at an angle of incidence of $60 ^ { \circ }$ and the reflected beam is completely Plane polarised. Find the refractive index of this glass

  1. $\sqrt { 2 }$
  2. $\sqrt { 3 / 2 }$
  3. $\sqrt { 3 }$
  4. $\cfrac { 3 } { 2 }$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Refractive index mu = tan(i_p) = tan(60) = sqrt(3).

Multiple choice polarisation of light polarisation wave optics optics physics

If the polarizing angle for a given medium is $60^{\circ}$, then the refractive index of the medium is 

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

  3. 2
  4. $\sqrt{3}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Refractive index mu = tan(i_p) = tan(60) = sqrt(3).

Multiple choice polarisation of light polarisation wave optics optics physics

A polarizer and an analyzer are arranged with their optic axes parallel to each other Symmetric light first passes through the polarizer and then the analyzer and the intensity of the light emerging is 'I'. If the analyzer is turned through $30^o$, the percent changes in the intensity is

  1. $75\%$
  2. $50\%$
  3. $25\%$
  4. $40\%$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Initial intensity I = I_0. After turning 30 degrees, I' = I_0 * cos^2(30) = I_0 * 3/4. The change is I_0 - 0.75I_0 = 0.25I_0, which is 25%.

Multiple choice polarisation of light polarisation wave optics optics physics

When unpolarized light beams are incidents in the air into glass ($n=1.5$ at polarising angle)

  1. reflected beams is $100$ polarised

  2. reflect and refracted beams are partially polarised

  3. the reason for (a) is that almost all the light is reflected

  4. all the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When unpolarized light is incident at Brewster angle from one medium to another, the light that is reflected from the surface is perfectly polarized

Multiple choice polarisation of light polarisation wave optics optics physics

Dichorism means

  1. selective absorption of unpolarised light.

  2. selective absorption of dispersed light.

  3. selective absorption of scattered light.

  4. selective absorption of one of the polarised component.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dichromism is the selective absorption of one orthogonal polarization component of an incident beam over the other. this phenomenon is due to anisotropy of the material, with one polarization component experiencing preferential absorption.

Multiple choice polarisation of light polarisation wave optics optics physics

From Brewster's law, it follows that the angle of polarization depends upon

  1. the wavelength of light

  2. orientation of the plane of polarization

  3. orientation of the plane of vibration

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\theta _B=tan^{-1}\dfrac{n _2}{n _1}$

Since the refractive index for a given medium changes depending on the wavelength of light, Brewster's angle will also vary with wavelength.