Monday , January 18 2021

# 10 Science Solved Sample Paper 4

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 4 – Page 1

## Section A

#### Question: 1. Suggest any two reasons which make the large scale usage of nuclear energy prohibitive. [1]

Answer: Two reasons are:

1. None-availability of nuclear fuel like u-235 on large scale.
2. Fear of leakage of harmful radiations from the nuclear power plants.

#### Question: 2. Give one example each of unisexual and bisexual flowers. [1]

Answer: Unisexual: Papaya, Watermelon; Bisexual: Hibiscus, Mustard

## Section B

#### Question: 3. The speed of light in vacuum is 3 × 108 m/s. Find the absolute refractive index of a medium in which light travels with a speed of 1.4 × 108 m/s. [2]

Answer: Absolute refractive index of a medium = 2.14

#### Question: 4. After independence, the forest department of Government of India, ignoring the needs of local people introduced mono-culture of pine, teak and eucalyptus in vast tracts of forests. Explain how this practice affected the biodiversity of forest and also the daily life of the local people. [2]

1. Large amount of biodiversity was destroyed.
2. Varied needs of local people like fodder for animals, herbs for medicines, fruits and nuts for food for animals, could no longer be met.

#### Question: 5. (1). Name the gland which releases thyroxin.(2). State the function of thyroxin. [2]

1. Thyroid gland
2. Thyroxin hormone controls the metabolism of carbohydrates, fats and proteins in our body.