Physics · Science General

Optics and Light Properties

2,019 Questions

Optics and light properties focus on the behavior of light, including reflection, refraction, dispersion, and polarization. This topic also covers the wave nature of light, illumination, and the functioning of optical instruments like microscopes. Questions on these concepts are common in general science sections of SSC, Railways, and State exams.

Reflection and mirrorsRefraction and mediumsLight wave theoriesPolarization and intensity

Optics and Light Properties Questions

Multiple choice physics wave optics difference between interference and diffraction explaining wave phenomena diffraction

In Fresnel's bi-prism experiment, the coherent sources are obtained by

  1. interference

  2. reflection

  3. refraction

  4. total internal reflection
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Fresnel bi-prism, light from the single source are made into two virtual sources on passing it through the bi-prism due to refraction in prism, so that the two sources acts as a coherent sources

Multiple choice physics wave optics difference between interference and diffraction explaining wave phenomena diffraction

Which of the following statements is correct?

  1. Diffraction is because of interference of light from same sources whereas interference is due to light form two isolated sources.

  2. Diffraction is due to interaction of light from same wave fronts whereas interference is due to interaction of two waves derived from the same source.

  3. Diffraction is due to interference of waves derived from the same source whereas interference is bending of light from the same source.

  4. Diffraction is due to reflected waves whereas interference is due to transmitted waves from a source.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a same source is present, it might give different colours depending on the path difference between the interfering rays from the source.

However when two completely different sources are present, they interfere due to path difference between them and give the interference pattern. For example, Young' double slit experiment.

Multiple choice difference between interference and diffraction explaining wave phenomena diffraction
Monochromatic light beam passed through two narrow slits form a pattern of bright and dark lines on a screen. The phenomena causing this pattern is: 

  1. Refraction

  2. Reflection

  3. Polarization

  4. Interference

  5. Intensity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The waves pass through the double-slit and interfere with each other, creating nodes and antinodes on the screen, which we see as alternating bright and dark lines. 

Multiple choice difference between interference and diffraction explaining wave phenomena diffraction

Direction:
The question has a paragraph followed by two statements, Statement-1 and Statement-2. Of the given four alternatives after the statements, choose the one that describes the statements.
A thin air film is formed by putting the convex surface of a plane-convex lens over a plane glass plate. 
With monochromatic light, this film gives an interference pattern due to light reflected from the top (convex) surface and the bottom (glass plate) surface of the film. 
Statement -1 : When light reflects from the air-glass plate interface, the reflected wave suffers a wave change of $\pi $
Statement-2: The centre of the interference pattern is dark

  1. Statement-1 is true, Statement-2 is false.

  2. Statement-1 is true, Statement-2 is true, Statement-2 is the correct explanation of Statement-1

  3. Statement-1 is true, Statement-2 is true, Statement-2 is not the correct explanation of Statement-1

  4. Statement-1 is false, Statement-2 is true
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As the center of the pattern is dark, we know that the phase difference is $(2n+1)\pi$. Furthermore, we also know that for the center of the interface pattern, there is no path difference. So the difference can only be due to reflection which is $\pi$. Therefore, both the assertion and the reason are correct and the reason is explanatory,

Multiple choice difference between interference and diffraction explaining wave phenomena diffraction

If a torch is used in place of monochromatic light in Young's experiment what will happens?

  1. Fringe will appear for a moment then, it will disappear

  2. Fringes will occur as from monochromatic light

  3. Only bright fringes will appear

  4. No fringes will appear
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A torch emits white light, which is a mixture of many wavelengths. Each wavelength produces its own interference pattern, and these patterns overlap, washing out the fringes.

Multiple choice

Which of the following is an example of light interference?

  1. light that is blocked by a wall

  2. light that is absorbed by a black shirt

  3. the spectrum of colors reflected on a soap bubble

  4. translucent light shining through a lamp shade
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The colors seen on a soap bubble are caused by thin-film interference, where light waves reflecting off the inner and outer surfaces of the film overlap and interfere constructively or destructively.

Multiple choice

Which of the following does NOT determine the color of objects we see?

  1. the light that is reflected back

  2. the speed with which that light travelled

  3. the light that is absorbed

  4. the amount of available light
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The color of an object is determined by which wavelengths of light are reflected and which are absorbed. The speed of light is constant in a given medium and does not determine the color of an object.