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 evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

If a plane mirror makes an angle of ${120^0}$ with x-axis, then  a ray of light, incident on it along x-axis, after reflectionmay pass through point.

  1. (1,1)
  2. $\left( {1,\sqrt 3 } \right)$

  3. (3,1)

  4. (1,2)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mirror is at 120 degrees to the x-axis. A ray along the x-axis hits the mirror at an angle of 60 degrees relative to the normal. By reflection laws, the reflected ray makes an angle of 120 degrees with the x-axis. The line equation is y = -sqrt(3)x + c. Testing the point (1, sqrt(3)) fits the geometric path.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

We can see the objects only when:

  1. reflected light from the objects reaches our eyes

  2. the objects absorb all the light

  3. when the objects allow all the light to pass through them

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

Objects can pnly be seen when light falls onto the object and is reflected back to our eyes to form an image on the retina.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

Light waves:

  1. require air or another gas to travel through

  2. require an electric field to travel through

  3. require a magnetic field to travel through

  4. can travel through perfect vacuum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Light is an electromagnetic wave which is transverse in nature. It does not require any material medium to pass through and can travel through vacuum.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

Find out the only wrong statement in the following:

  1. Light travels with a speed greater than that of sound

  2. Light cannot travel through vacuum

  3. Light travels in a straight line

  4. Light has no weight
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Light is an electromagnetic wave which is transverse in nature. So, it does not require any material medium to pass through. Light, thus, can travel through vacuum.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

We can see an object from every direction due to ____________ of the incident light ray on the object.

  1. regular refraction

  2. regular reflection

  3. irregular reflection

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

Irregular reflection makes us see all the objects and everything around us. If light gets regularly reflected then every object would act like a mirror and our surroundings would be illuminated. This would have a blinding effect on eyes making it harder for us to see.

Multiple choice evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

A leaf which contains only green pigments, is illuminated by a laser light of wave length 0.6328 $\mu$ m. It wound appear to be:

  1. Brown

  2. Black

  3. Red

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

0.6328 $\mu m$ = $6328 \mathring A$
This is wavelength of red colour. So, this light will be absorbed by green pigments. 
The leaf will appear black.