Introduction to Lenses

Q.

What is aperture

Q.

What is an aperture in the lens?

1. The distance between A & O

2. The distance between A & B

3. The distance between O & B

4. The distance between C & D

Q. Why the object lens is smaller in compound microscope compare to astronomical telescope?

Q.

Stars appear to twinkle in the sky due to ______ of light.

Q. What is the reason of the twinkling of stars?

1. Reflection
2. Dispersion
3. Scattering
4. Refraction

Q. Briefly explain the working principle of lenses.

Q. While driving in winters through a dense fog, we can see some rays emitted by the headlights of the vehicle reaching towards us. This is due to:

1. atmospheric refraction
2. reflection of light
3. scattering of light
4. dispersion of light

Q. What is mean by dispersive power of a transparent material?

Q. Convex lenses are always tapering in the middle and thicker at the edges.

Q.

At what position does a magnifying glass is kept to manify the object?

Q.

Observe the optical systems above. Given that all surfaces are made of transparent glass and the dotted surfaces represent plane surface. Which among them can be considered as lenses?

1. I, II, IV, V

2. I, II, III, V

3. I, II, III, IV

4. I, IV only

Q. The working principle of lenses is ___.

1. reflection
2. dispersion
3. scattering
4. refraction

Q. Rainbow is a natural example of dispersion of light.

1. True
2. False

Q. Which of the following statements is true?

1. Concave lenses are also called converging lenses.
2. Concave lenses can both converge and diverge the rays falling on them.
3. Convex lenses are also called converging lenses.
4. Convex lenses are also called diverging lenses.

Q. What happens when a beam of sunlight enters a dusty room through a window? Explain your answer.

Q. Dispersion of light as seen in a prism can also be observed in a rectangular glass slab.

1. True
2. False

Q. A light ray passing through a spherical lens undergoes refractions.

1. two
2. one
3. four

Q. Tiny air particles reflect the incoming sunlight in all directions. This is known as scattering of light.

1. True
2. False

Q. Arrange the following colors in ascending order of their deviation through prism.

1. Red
2. Green
3. Blue
4. Yellow
5. Violet

Q. Early sunrise and delayed sunset happens due to atmospheric refraction.

1. True
2. False

Q. Which of the following is an appropriate condition for a thin lens?

1. Aperture << Radius of curvature

2. Aperture >> Radius of curvature

3. Aperture = Radius of curvature

4. Aperture is more than the focal length.