# Samacheer Kalvi 7th Science Term 3 Unit 1 Solutions

## Samacheer Kalvi 7th Science Term 3 Unit 1 Book Back Question and Answers/Solutions:

Samacheer Kalvi Class 7th Std Science Book Back 1 Mark and 2 Mark Question & Answers PDF uploaded and available below. Class 7th Standard New Syllabus 2022 to 2023 Book Back Question & Answer solutions available for both English and Tamil Medium. Class 7 New Science Book Term 3 Unit 1 – Light Answers/Solutions Guide are provided on this page. 7th Std Science Book is of 1st Term consists of 7 units, 2nd and 3rd Term consists of 6 units. All Units/Chapters of Term 1st, 2nd, 3rd Science Book Back One, and Two Mark Solutions are given below.

Check Unit wise and  7th New Science Book Back Question and Answers Guide/Solutions PDF format for Free Download. 7th Std English, Tamil, Maths, Science, and Social Science Book Back Questions and Answers available in PDF. Check Science Book Back Solutions below. See below for the Samacheer Kalvi 7th Science Term 3 Chapter 1 Book Back Answers PDF:

### Samacheer Kalvi 7th Science Book Back Chapter 1 Term 3 Answers/Solutions Guide PDF:

7th Science Subject 1 Mark and 2 Mark Solutions Guide PDF available below. Click the Download option to download the book back 1 Mark & 2 Mark questions and answers. Take the printout and use it for exam purposes.

### Light

I. Choose the correct option:

1. Light travels only in a ______ .It is because of this property that.
(c) straight line, reflection
(d) curved line and then straight line, shadows

2. Light that hits a mirror gets ______
(a) Transmitted
(b) Reflected
(c) Absorbed
(d) Refracted

3. ______ surface reflects the light well
(a) Water
(b) Compact disc
(c) Mirror
(d) Stone

4. Light is a form of ____
(a) matter
(b) energy
(c) medium
(d) partical

5. You can see your image in polished floors, but not in wooden table because ______
(a) regular reflection takes place in wooden table and irregular reflection in polished floor
(b) regular reflection takes place in polished floor and irregular reflection in wooden table
(c) regular reflection takes place in both polished floor and wooden table
(d) irregular reflection takes place in both polished floor and wooden table
Answer: (b) regular reflection takes place in polished floor and irregular reflection in wooden table

6. Choose the translucent substance from the following
(a) glass
(b) wood
(c) water
(d) Clouds

7. Reflection occurs , when the light
(a) about to reach a surface
(b) approaches a surface
(c) passes through a surface
(d) None Of these

8. Which of the following is the best reflector
(a) plastic plate
(b) plane mirror
(c) wall
(d) paper

9. Sivarajan placed a meter stick in the playground at 7.00 am in the morning. How will the shadow of the stick at noon look in comparison to the one in the morning
(a) There will be no shadow
(b) The shadow will be longer and on the opposite side as the sun
(c) The shadow will be shorter and on the same side as the sun
(d) The shadow will be shorter

10. The image formed by a pinhole camera is inverted because,
(a) light travels in straight lines
(b) light rays become laterally inverted as they pass through a pinhole camera
(c) light rays pass through the pinhole
(d) light rays get reflected
Answer: (a) light travels in straight lines

11. Which of the following facts explain how shadows are formed?
(a) Light travels in straight lines
(b) Opaque bodies do not allow light to pass through them
(c) Reflection occurs at a smooth surfaces like mirrors
(d) Lateral inversion happens
(a) both A and B
(b) both A and D
(c) both B and C
(d) only A
Answer: (a) both A and B

### II. Fill in the blanks:

1. A plane mirror produces a _________ image
2. A _________ reflection helps us to see the objects.
3. The light ray gets _________ when it falls on any polisher surface
4. Sunlight is a blend of _________ colours
5. The splitting of white light into seven colours is called _________
6. The moon _________ sun light.
7. The sunlight can be split into its constituent colours using _________
8. Reflection of light from rough surface is called _________ reflection

1. virtual and erect
2. regular
3. reflected
4. seven
5. dispersion
6. reflects
7. prism
8. irregular

### III. Say TRUE or FALSE:

1.The image of right hand in a plane mirror looks like a left hand.

2. Rainbow is formed by dispersion of which light by water drops.

3. The image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is also laterally inverted
Correct statement: The image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is This is because in periscope, image is reflected by two mirrors.

4. We see planets because they reflect light from the sun

5. We see a book because it reflects the light that falls on its surface

6. The image formed in a pinhole camera is always inverted

7. The image formed in a pinhole camera is always the satne size as the object

8. The image formed in a plane mirror is upside down
Correct statement: The image formed in a plane mirror is erect.

9. A plane mirror is opaque Ans.

10. A shadow is formed on the same side of the object as the source of light.
Correct statement: A shadow is formed on the side of the object as the source of light.

11. We are able to see things around us with the help of regular reflection

12. After passing through a prism, white light splits into a band of seven colours