English Medium कक्षा १० - CBSE Question Bank Solutions for Science

1. 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.
2. Show the lateral displacement of the ray on the diagram.

 Show the lateral displacement of the ray on the diagram. 

State two factors on which the lateral displacement of the emergent ray depends.

Explain with the help of a labelled ray diagram, why a pencil partly immersed in water appears to be bent at the water surface. State whether the bending of pencil will increase or decrease if water is replaced by another liquid which is optically more dense than water. Give reason for your answer.

Light travelling from a denser medium to a rarer medium along a normal to the boundary:

(a) is refracted towards the normal
(b) is refracted away from the normal
(c) goes along the boundary
(d) is not refracted

When a ray of light travelling in glass enters into water obliquely ______.

A ray of light passes from a medium X to another medium Y. No refraction of light occurs if the ray of light hits the boundary of medium Y at an angle of:

(a) 0°
(b) 45°
(c) 90°
(d) 120°

A vertical ray of light strikes the horizontal surface of some water:

1. What is the angle of incidence?
2. What is the angle of refraction?

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?

How does the light have to enter the glass: 

 for no refraction to happen? 

Define the principal focus of a concave mirror.

Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 10⁸ m s⁻¹.

What is atmospheric reflection? Explain with the help of a labelled diagram that the position of a star as seen by us is not its true position. 

List four characteristics of the image formed by a concave lens of focal length 20 cm when the object is placed at a distance of 40 cm from its optical centre. 

The size of image of an object by a convex lens of focal length 20 cm is observed to be reduced to  `1/3` rd of its size . Find the distance of the object from the optical centre of the lens . 

List in proper sequence the steps of the experiment for determining the approximate focal length of a given concave mirror by obtaining the image of a distant object.

A real image is formed by the light rays after reflection or refraction when they:

1. actually meet or intersect with each other.
2. actually converge at a point.
3. appear to meet when they are produced in the backward direction.
4. appear to diverge from a point.

Which of the above statements are correct?

The laws of reflection hold true for ______.

You are given water, mustard oil, glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?