English Medium कक्षा १० - CBSE Important Questions

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

What happens to the image distance in the eye when we increase the distance of an object from the eye?

Explain why the planets do not twinkle.

A person is unable to read a book placed closer than 1 meter from his eyes. Identify the defect of vision in his eyes. Draw the ray diagrams to show the defect of vision and its correction.

In the following diagram, the correctly marked angles are

(A) All
(B) Only ∠i and ∠A
(C) ∠i, ∠r and ∠A
(D) ∠i, ∠A and ∠D

In an experiment to trace the path of a ray of light through a triangular glass prism, a student would observe that the emergent ray

(a) is parallel to the incident ray.

(b) is along the same direction of incident ray.

(c) gets deviated and bends towards the thinner part of the prism.

(d) gets deviated and bends towards the thicker part (base) of the prism.

In which of the following four diagrams is the correct path of a ray of light passing through a glass prism shown ?

State one role of ciliary muscles in the human eye.

Draw a labeled ray diagram to illustrate the dispersion of a narrow beam of white light when it passes through a glass prism.

An old man cannot see objects closer than 1 m from the eye clearly. Name the defect of vision he is suffering from. How can it be corrected? Draw ray diagram for the (i) defect of vision and also (ii) for its correction.

The stars appear higher from horizon than they actually are. Explain why it is so.

Explain why the planets do not twinkle but the stars twinkle.

What eye defect is hypermetropia? Describe with a ray diagram how this defect of vision can be corrected by using an appropriate lens.

What is Hypermetropia (far sightedness)? 

Draw a ray diagram to show how Hypermetropia is defect can be corrected using a lens.

A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so. 

List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision. 

When do we consider a student sitting in the class to be myopic? List two causes of this defect. Explain using a ray diagram how this defect of eye can be corrected.

The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?

What is the cause of the dispersion of white light through a glass prism? Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in an inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the faces of the prisms.