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 reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

You are given four sources of light each one providing a light of a single colour red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90. Which of the following statements is correct, if the source of yellow light is replaced with that of other lights without changing the angle of incidence?

  1. The beam of red light would undergo total internal reflection.

  2. The beam of red light would bend towards normal while it gets refracted through the second medium.

  3. The beam of blue light would undergo total internal reflection.

  4. The beam of green light would bend away from the normal as it gets refracted through the second medium.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For yellow light, r=90$^{\circ}$, when $i=c$ since $i$ is kept $c$ should be smaller for total reflection

$\mu = \cfrac{1}{\sin{c}}$ 
If $c$ is small, $\mu$ will be large.
$\therefore c $ will be smallest for this colour.
Hence, blue colour will undergo total internal reflection.

Multiple choice physics reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

Regular reflection takes place when light is incident on:

  1. a rough curved surface

  2. a highly polished plane surface

  3. either of A and B

  4. neither of A and B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When parallel rays of light are incident on a highly polished plane surface, after reflection, the rays emerge parallel as well. This type of reflection is called regular reflection.

Multiple choice physics reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

Irregular reflection occurs due to:

  1. failure of laws of reflection

  2. irregularity in reflecting surface

  3. irregular light

  4. all of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Irregular reflection occurs when parallel rays of light are incident on an irregular or rough surface and after reflection emerge in different directions. This type of reflection occurs due to irregularity of the reflecting surface.

Regular reflections occur from smooth or polished surfaces.

Multiple choice physics reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

Mark the statement which is true for diffused reflection:

  1. Diffused reflection is due to failure of laws of reflection

  2. It is caused due to irregularities in the reflecting surface

  3. When the incident light is diffused in nature it causes diffused reflection

  4. All are true
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Diffused reflection is not due to failure of laws of reflection but it is due to irregularities in the reflecting surface, like that of cardboard.

Multiple choice physics reflection of light and shadow regular and irregular reflection regular and diffused reflection laws of reflection

Diffused reflection

  1. may produce image

  2. never produce image

  3. must produce image

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

Diffused reflection occurs on rough surfaces. While it scatters light, it can still form images if the surface is not perfectly irregular, though they are often less sharp than those from specular reflection.

Multiple choice physics dual nature of matter and radiation davisson and germer experiment and its conclusion matter waves wave nature of matter

Electrons can be diffracted (Davis-son and German's expt.).

  1. Yes, as their wave is transverse.

  2. Yes, as their wave is longitudinal

  3. No, as their wave is longitudinal

  4. No, as they travel in a straight line.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As electron waves oscillation is confined in one orientation only, therefore  it cannot be polarized.

Multiple choice commercial applications sources of water conservation of natural and energy resources energy conservation and sources importance of the conservation of natural resources reduce, recycle, reuse

CFL is

  1. Chlorofluoro lamp

  2. Compact fluorescent lamp

  3. Compact fluorescent light

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

CFL is compact fluorescent light. Compact fluorescent light bulbs are used in place of incandescent bulb because they use about 1/7$^{th}$ of the power used by the incandescent bulb. Hence, they are highly efficient in saving electricity.

Thus, the correct answer is option C.