Advertisements
Advertisements
Question
With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.
Advertisements
Solution
In the following figure, a light ray travelling in air is incident on the rectangular glass slab. It gets refracted and bends towards the normal. Again, a change in the direction takes place when the refracted ray travelling in glass emerges into air. Here, the light ray bends away from the normal. We see that the incident and emergent rays are parallel to each other. These rays are parallel because the extent of bending on the opposite and parallel faces of slab is equal and opposite.
APPEARS IN
RELATED QUESTIONS
What type of reflection of light takes place from a cinema screen?
Explain why, though both a plane mirror and a sheet of paper reflect light but we can see the image of our face in a plane mirror but not in a sheet of paper.
The image in a plane mirror is virtual and laterally inverted. What does this statement mean?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
Show the lateral displacement of the ray on the diagram.
A vertical ray of light strikes the horizontal surface of some water:
What is the angle of refraction?
How does the light have to enter the glass:
to produce a large amount of bending?
Water is optically denser than glass.
The depth of a pond when seen from above appears to be less.
When a ray of light travels from water to air, it bends ............. the normal.
What do you understand by refraction of light?
Draw suitable diagrams to illustrate how a beam of light incident parallel to the principal axis is reflected by:
(a) a concave mirror, and (b) a convex mirror
A ray of light A incident from air suffers partial reflection and refraction at the boundary of water.
- Complete the diagram showing (i) the reflected ray B and (ii) the refracted ray C.
- How are the angles of incidence i and refraction r related?
Write scientific reason.
A pencil appears to be broken near the surface of water.
Why does a ray of light bend when it travels from one medium to another?
Assertion and reasoning type
- Assertion: If the refractive index of the medium is high (denser medium) the velocity of the light in that medium will be small
- Reason: Refractive index of the medium is inversely proportional to the velocity of the light
What is refractive index?
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
Why a pencil partly immersed in water appears to be bent at the water surface.
