• Home
  • Textbooks
  • NCERT Class 10 Science
  • Light - Reflection and Refraction

NCERT Class 10 Science

M. Siraj Anwar, Shweta Uppal

Chapter 10

Light - Reflection and Refraction - all with Video Answers

Educators

Chapter Questions

01:19

Problem 1

Which one of the following materials cannot be used to make a lens?
(a) Water
(b) Glass
(c) Plastic
(d) Clay

Ashok Prajapati
Ashok Prajapati
Numerade Educator
02:51

Problem 2

The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
(a) Between the principal focus and the centre of curvature
(b) At the centre of curvature
(c) Beyond the centre of curvature
(d) Between the pole of the mirror and its principal focus.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
02:01

Problem 3

Where should an object be placed in front of a convex lens to get a real image of the size of the object?
(a) At the principal focus of the lens
(b) At twice the focal length
(c) At infinity
(d) Between the optical centre of the lens and its principal focus.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:56

Problem 4

A spherical mirror and a thin spherical lens have each a focal length of $-15 \mathrm{~cm}$. The mirror and the lens are likely to be
(a) both concave.
(b) both convex.
(c) the mirror is concave and the lens is convex.
(d) the mirror is convex, but the lens is concave.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:40

Problem 5

No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be
(a) only plane.
(b) only concave.
(c) only convex.
(d) either plane or convex.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:55

Problem 6

Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
(a) A convex lens of focal length $50 \mathrm{~cm}$.
(b) A concave lens of focal length $50 \mathrm{~cm}$.
(c) A convex lens of focal length $5 \mathrm{~cm}$.
(d) A concave lens of focal length $5 \mathrm{~cm}$.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
05:32

Problem 7

We wish to obtain an erect image of an object, using a concave mirror of focal length $15 \mathrm{~cm}$. What should be the range of distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object? Draw a ray diagram to show the image formation in this case.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
02:32

Problem 8

Name the type of mirror used in the following situations.
(a) Headlights of a car.
(b) Side/rear-view mirror of a vehicle.
(c) Solar furnace.
Support your answer with reason.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:45

Problem 9

One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.

Pritesh Ranjan
Pritesh Ranjan
Numerade Educator
04:27

Problem 10

An object $5 \mathrm{~cm}$ in length is held $25 \mathrm{~cm}$ away from a converging lens of focal length $10 \mathrm{~cm}$. Draw the ray diagram and find the position, size and the nature of the image formed.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
04:40

Problem 11

A concave lens of focal length $15 \mathrm{~cm}$ forms an image $10 \mathrm{~cm}$ from the lens. How far is the object placed from the lens? Draw the ray diagram.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
02:10

Problem 12

An object is placed at a distance of $10 \mathrm{~cm}$ from a convex mirror of focal length $15 \mathrm{~cm}$. Find the position and nature of the image.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:52

Problem 13

The magnification produced by a plane mirror is $+1 .$ What does this mean?

Ashok Prajapati
Ashok Prajapati
Numerade Educator
04:11

Problem 14

An object $5.0 \mathrm{~cm}$ in length is placed at a distance of $20 \mathrm{~cm}$ in front of a convex mirror of radius of curvature $30 \mathrm{~cm}$. Find the position of the image, its nature and size.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
03:21

Problem 15

An object of size $7.0 \mathrm{~cm}$ is placed at $27 \mathrm{~cm}$ in front of a concave mirror of focal length $18 \mathrm{~cm}$. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained? Find the size and the nature of the image.

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:29

Problem 16

Find the focal length of a lens of power $-2.0 \mathrm{D}$. What type of lens is this?

Ashok Prajapati
Ashok Prajapati
Numerade Educator
01:31

Problem 17

A doctor has prescribed a corrective lens of power $+1.5 \mathrm{D}$. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Ashok Prajapati
Ashok Prajapati
Numerade Educator