Focus of a Convex Lens

Q.

In a convex lens, ray parallel to the principal axis after refraction passes through which of the following?

1. Cannot be determined

2. centre of curvature

3. focus

4. optical centre

Q.

A light ray passing through the optic centre of a convex lens will pass through ___ after refraction.

1. principal focus

2. centre of curvature

3. It will not deviate from its path

4. a point between optic centre and focus

Q.

Question 17
Which of the following ray diagram is correct for the ray of light incident on a lens as shown in figure 1?


(a) Fig. A.
(b) Fig. B.
(c) Fig. C.
(d) Fig. D.

Q.

Which of the following is true about lenses?

1. convex mirror has negative focal lengths concave lens have positive focal length

2. convex mirror has positive focal length and concave lens have positive focal length

3. convex mirror has positive focal length and concave lens have negative focal length

4. both convex mirror and convex lens have negative focal length.

Q. Where would the image form, if the object is placed at a finite distance from a concave lens?

1. At optical centre
2. Between Center of curvature and focus
3. Between focus and optical centre
4. At Focus

Q. A person needs a lens of power $-2.5D$ for correcting his vision. What is the defect of vision that the person is suffering from? Also, find the focal length of the lens.

1. Hypermetropia, $0.4m$
2. Myopia, $0.4m$
3. Myopia, $-0.4m$
4. Hypermetropia, $-0.4m$

Q. Where would the image form, if the object is placed at a finite distance from a concave lens?

1. Between Center of curvature and focus
2. At Focus
3. At optical centre
4. Between focus and optical centre

Q.

If a ray passing through the focus gets refracted by a convex lens, where will it intersect the principal axis?

1. At focus on the other side.

2. At the pole of the lens.

3. At double the focal length on the other side.

4. Does not intersect at all.

Q. In which of the following cases a light ray suffers the maximum deviation while passing through pole?

1. 
2. 
3. 
4. 

Q. In an astronomical telescope the focal lengths of objective and eyepiece should respectively be :

1. large and small
2. small and large
3. equal
4. too small are too large

Q.

If $F_1$ and $F_2$ represents the foci of the lens, then at which point will the light rays meet?

1. $F_1$

2. $2F_1$

3. $F_2$

4. $2F_2$

Q. Where would the image form, if the object is placed at a finite distance from a concave lens?

1. Between Center of curvature and focus
2. At Focus
3. Between focus and optical centre
4. At optical centre

Q. Where would the image form, if the object is placed at a finite distance from a concave lens?

1. Between Center of curvature and focus
2. At Focus
3. At optical centre
4. Between focus and optical centre

Q.

In a convex lens, ray parallel to the principal axis after refraction passes through which of the following?

1. through centre of curvature

2. through optical centre

3. through focus

4. parallel to principal axis

Q.

Parallel rays of light entering a convex lens converge at:

1. Centre of curvature

2. Optical centre

3. Principal focus

4. Secondary focus