The distance between the pole and centre of curvature of a spherical mirror, in terms of its focal length f. is equal to

What number of lenses are used in a compound microscope?

The focal length of a convex lens is 15 cm and an object is placed at 18 cm. Then the image formed will be?

The S.I. unit of focal length is:

Which of the following statements is true for a converging lens?

A convex mirror used as a rear-view mirror of a car has a focal length of 2 m. Ifa bus is located at a distance of 3 m from the mirror, where will its image be formed?
 

Which type of mirror is used in a dental mirror to see a magnified view of teeth?

What is the distance between the pole and focus of a spherical mirror?

For a person with Hypermetropia or far-sightedness, the near point, is ________farther away from the normal near point.

An image which can be obtained on a screen is called a _________________.

Which kind of mirrors is used as rear view wing mirrors in vehicles?

If a lens has a focal length of 25 cm, what will be the power of that lens?

In which type of lens does light converge to a point on the other side of the object?

If the power of the lens of a spectacle is +2 D, then what will be its focal length?

Find the power of a concave lens of focal length 5m.

What is the principal focus of a spherical mirror?

What is the Centre of Curvature of a spherical mirror?

Which of the following statements is/are true about the principal axis of a spherical mirror?

(i) It is normal to the mirror.

(ii) The point of incidence always lies on the principal axis.

(iii) Principal focus always lies on the principal axis.

What is the main difference between a positive lens and a negative lens?

For which situation does a convex lens always form a virtual image?

What happens to the focal length of a lens when it is immersed in a medium with a refractive index higher than that of the lens material?

A student focusses a sharp image of sun using a spherical mirror on a sheet of paper, which starts to burn after some time.

Which of the following statement/statements about the mirror is’are correct?

(a) It is concave spherical mirror

(b) It has positive focal length

(c) It is a converging mirror
 

Which statement about the image formed by a convex lens when an object is placed at twice the focal length is true?

Which of the following types of images can be obtained on a screen?

(a) Real and enlarged

(b) Real and diminished

(c) Virtual and enlarged

(d) Virtual and diminished

If a ray of light is incident passing through the centre of curvature of a concave mirror, then the angle between the incident ray and the reflected ray will be equal to:

The focal length of a convex mirror is:

An object placed 30 cm from a concave lens forms a virtual erect image at a distance of 10 cm from the lens. The magnification produced by the lens is:

The distance between the focus and the centre of curvature of a spherical mirror in terms of the radius of curvature R, is equal to:

What is the Centre of Curvature of a spherical mirror?

What are the uses of the convex lens?

What is the main difference between a positive lens and a negative lens?

If the power of the lens of a spectacle is +2 D, then what will be its focal length?

This is NOT a use of a concave mirror:

What is the primary function of a concave lens in optical instruments?

A flat window has an optical power of how many dioptres

Which kind of mirrors is used as rear view wing mirrors in vehicles?

Which type of mirror is used in blind corners of roads?

In which type of lens does light converge to a point on the other side of the object?

What number of lenses are used in a compound microscope?

Which of these does NOT have an optical lens?