Rules of Ray Diagram for Representation of Image

Q.

Choose the correct ray diagram:

1. 

2. None of these

3. 

4. 

Q. When an object is placed between the principal focus and the optic centre of a convex lens, the resulting image distance would be .

1. positive
2. negative
3. zero

Q. A convex mirror always forms a virtual, erect, and diminished image, irrespective of the position of the object.

1. True
2. False

Q.

A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray passes through :

(a) its optical centre

(b) its first focus

(c) its second focus

(d) the centre of curvature of the first surface.

Q.

What happens when a ray parallel to the principal axis passes through a concave lens?

Q. What are coaxial lenses and where are they used?

Q.

A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from :

(a) its first focus

(b) its optical centre

(c) its second focus

(d) the centre of curvation of its second surface.

Q.

A ray starting from the focus of a concave lens becomes parallel to the principal axis after refraction.

1. False

2. True

Q.

A ray of light passes undeviated after refraction from a thin convex lens when the ray is incident at __.

1. focus

2. centre of curvature

3. optical centre

4. parallel to principal axis

Q.

A lens forms an erect, magnified, and virtual image of an object. (a) Name the kind of lens. (b) Where is the object placed in relation to the lens ? (c) Draw a ray diagram to show the formation of image. (d) Name the device which uses this principle.

Q.

A ray of light incident parallel to the principal axis of a spherical mirror retraces its path.

1. True

2. False

Q. The central point of the lens through which light passes undeviated is known as ___.

1. optical centre
2. centre of curvature
3. aperture
4. principal axis

Q.

A ray of light after refraction through a convex lens emerges parallel to the principal axis. (a) Draw a ray diagram to show it. (b) The incident ray passes through a point F on the principal axis. Name the point F.

Q.

What is the optical centre of a lens?

1. All of the above

2. A point in or outside the lens through which a ray of light passes undeviated.

3. A line joining the centre of curvature of two spherical surfaces forming lens.

4. The vertical plane passing through the first principal focus.

Q. A real image of an erect object is always upright.

1. True
2. False

Q.

Which of the following has virtual focus?

1. concave lens

2. convex lens

3. convex mirror

4. both (a) and (c)

Q.

A point on a thin lens, through which light ray passes without any deviation is called ______________.

1. centre of curvature

2. optical centre

3. focus

4. second focus

Q. If the boy looks through the tube with 4 mirrors fixed at 45 degrees. How far the ball will appear from the boy?

1. 
   F - (A + E)
2. 
   F
3. A + B + C + D + E
4. 2F

Q. Why convex lens converge the ray of light and in convex mirror it diverge the ray of light.

Q.

Find $\theta$ if the light is falling on the pole?

1. ${60}^{\circ }$

2. ${30}^{\circ }$

3. ${90}^{\circ }$

4. ${150}^{\circ }$

Q. In the following diagram, the radius of curvature is and the object distance is .

1. $-26cm$
2. $-22cm$
3. $+22cm$
4. $+26cm$

Q. For practical purposes, we always consider the rays close to the Principal Axis.

1. True
2. False

Q.

If a ray passing through the focus hits the 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. Doesn’t intersect at all

Q. Calculate the focal length of the thin lens shown in the figure. The points $C_1$ and $C_2$ denote the centres of curvature.

1. 20 cm
2. 40 cm
3. 60 cm
4. 80 cm

Q. State the condition when a lens is called an equi-convex or equi-concave.

1. When radii of curvature of the two surfaces of lens are equal.
2. When radii of curvature of the two surfaces of lens unequal.
3. When height of the two lens are equal.
4. None of the above

Q. Choose the correct pair based on the position of the object and the image formed by a convex lens.

1. At infinity

Q.

In the given mirror

C – The center of the sphere to which the mirror is part of

F – The focus of the mirror

P – Pole of mirror

A – Point on the mirror

D – The point on the principal axis.

If a ray of light starts from C and is incident on A from which point will the reflected ray pass through:

1. D

2. C

3. F

4. P

Q.

Light rays passing through the centre of curvature of a mirror are incident normally on the surface of the mirror.

1. True

2. False

Q.

Tell whether the blue figure is a dilation of the red figure.

Q. Where should an object be placed in front of a convex lens to get a real image of the size of the object?

1. Between the optical centre of the lens and its principal focus
2. At the principal focus of the lens
3. At twice the focal length
4. At infinity