Advertisements
Advertisements
Question
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
Options
its optical centre
its first focus
its second focus
its centre of curvature of the first surface
Advertisements
Solution
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through its first focus.
APPEARS IN
RELATED QUESTIONS
State the condition when a lens is called an equi-convex or equi-concave.
Study the diagram shown in Fig. 5.56
where is the object located?

Study the diagram shown in Fig. 5.56
what are the two other characteristics of the image?

A ray of light incident at the optical centre of lens, passes undeviated after refraction.
State the condition of the following:
A lens has both its focal lengths equal.
State the condition of the following:
A ray passes undeviated through the lens.
Make the correct choices in the following items:
lf the image can be focused on a screen it must be
(a)A ray of light is incident at 45° on the face of
(i) A rectangular block of glass.
(ii) A 600 glass prism.
(b) Draw a sketch showing how the ray of monochromatic ray of light passes through glass in each case.
(c) With the aid of a diagram, explain how the face of a right angled prism may totally reflect incident on it.
(d) A thick plane mirror produces several faint images in addition to a prominent one. Draw a ray diagram showing how reflection and refraction produce all these images.
(e) Fig. represents a stone S at the bottom of a pond of water. Using the two rays, as shown, complete the ray diagram to show where the image of the stone appears when viewed from E.

(f) What is a''mirage'? Explain with the help of a diagram.
(g) A man observes the bottom of a swimming pool of 3 m depth. If the refractive index of water is 1.3, what is the apparent depth of water?
(h) When a ray of light undergoes refraction through a glass slab and when it emerges it is displaced laterally (Fig). What are the factors on which the lateral displacement depends?

(i) Fig. shows three rays of light OA, OB and OC passing from water to air, making angles 490, 410 and 350 with the horizontal surface respectively. Draw an approximate path of the emergent ray for each. (Critical angle of water is 490.)

A lens forms the image of an object placed at a distance of 45 cm from it on a screen placed at a distance 90 cm on the other side of it. Name the kind of lens.
Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F.
