10 Science Solved Sample Paper 3

As per 2019 CBSE Question Paper Design

Class: 10th Class CBSE
Subject: Science
Time Allowed: 3 Hours
Maximum Marks: 80

General Instructions:

• The question paper comprises five sections: A, B, C, D and E. You are to attempt both the sections.
• All questions are compulsory.
• Internal choice is given in sections B, C, E and E.
• Question numbers 1 and 2 in sections A are one marks questions. They are to be answered in one words or in one sentence.
• Question numbers 3 to 5 in sections B are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in sections C are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in sections D are five marks questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in sections E are based on practical skills. Each questions is a two marks question. These are to be answered in brief.

10 Science Solved Sample Paper 3 – Page 1

Section A

Question: 1. A solar cell transforms energy of one form into another. What are these two forms of energy? [1]

Answer: A solar cell transforms light energy into electrical energy.

Question: 2. Name the two components of central nervous system in humans. [1]

Answer: These two components are: (i) The Brain, (ii) Spinal cord.

Section B

Question: 3. What is a combination reaction? State one example giving balanced chemical equation for the reaction. [2]

Answer: When two or more substances combine to form one substance, then reactions are called combination reactions.
Example: C + O₂ —- Burning—→ CO₂↑

Question: 4. Draw a diagram showing flow of energy in an ecosystem. State the conclusion that can be drawn from this diagram. [2]

Answer: Flow of energy in the ecosystem is unidirectional, i.e., from producers to the last consumers.

Or
Why is there a need to harness non-conventional sources of energy? Give to main reasons.