CBSE Class 10 Science Sample Paper 2021 (with Answers & Marking Scheme)
CBSE Class 10 Science Sample Question Paper for Board Exam 2021 is provided here along with the answer hints and marking scheme. This sample paper is important to know the format of the Science question paper that you will get in the CBSE Board Exam 2021.
CBSE Class 10 Science Sample Paper for the Board Exam 2021 has been released by the board along with its marking scheme. CBSE sample paper is released to reveal the format of the question paper for the Class 10 Science Board Exam 2021. This paper also gives an idea about what type of questions can be expected in the exam. On the other hand, the marking scheme is helpful to know how the step-wise marking is followed during the evaluation of a candidate's answer sheet. This marking scheme also includes the suggested answers that help you understand how to include important keywords and concepts in your answers to score maximum marks.
Format of the CBSE Class 10 Science Sample Paper 2021:
(i) There are total 36 questions divided into four sections A, B, C and D.
(ii) Section - A: Question no. 1 to 20 - All questions and parts thereof are of one mark each. These questions contain multiple choice questions (MCQs), very short answer questions and assertion - reason type questions.
(iii) Section - B: Question no. 21 to 26 are short answer type questions, carrying 2 marks each.
(iv) Section - C: Question no. 27 to 33 are short answer type questions, carrying 3 marks each.
(v) Section - D: Question no. 34 to 36 are long answer type questions carrying 5 marks each.
Note: There is no overall choice. However, internal choices have been provided in some questions.
CBSE Sample Paper and Marking Scheme for Class 10 are provided here for free PDF download. So, do not miss to check this sample paper to make good preparation for your exam and score the desired marks.
CBSE Class 10 Science Sample Paper 2020
1. List any two observations when Ferrous Sulphate is heated in a dry test tube?
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 1g of Sodium metal?
2. Write the chemical name and chemical formula of the salt used to remove permanent hardness of water.
3. Which of the following is not observed in a homologous series? Give reason for your choice.
a) Change in chemical properties
b) Difference in -CH2 and 14u molecular mass
c) Gradation in physical properties
d) Same functional group
4. Why does the Sun appear white at noon?
5. Both a spherical mirror and a thin spherical lens have a focal length of (-)15 cm. What type of mirror and lens are these?
6. The image formed by a concave mirror is observed to be real, inverted and larger than the object. Where is the object placed?
Name the part of a lens through which a ray of light passes without suffering any deviation.
7. In the arrangement shown in figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted in the circuit. Later the key is inserted and then removed shortly after.
What are the two observations that can be noted from the galvanometer reading?
8. Draw the magnetic field lines around a straight current carrying conductor.
9. Two unequal resistances are connected in parallel. If you are not provided with any other parameters (eg. numerical values of I and R), what can be said about the voltage drop across the two resistors?
Some work is done to move a charge Q from infinity to a point A in space. The potential of the point A is given as V. What is the work done to move this charge from infinity in terms of Q and V?
10. Veins are thin walled and have valves. Justify.
11. How is the wall of small intestine adapted for performing the function of absorption of food?
Out of a goat and a tiger, which one will have a longer small intestine? Justify your answer.
12. Explain how ozone being a deadly poison can still perform an essential function for our environment. OR Give reason why a food chain cannot have more than four trophic levels.
13. State the role of pancreas in digestion of food.
For question numbers 14, 15 and 16, two statements are given- one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
a) Both A and R are true, and R is correct explanation of the assertion.
b) Both A and R are true, but R is not the correct explanation of the assertion.
c) A is true, but R is false.
d) A is false, but R is true.
14. Assertion: After white washing the walls, a shiny white finish on walls is obtained after two to three days.
Reason: Calcium Oxide reacts with Carbon dioxide to form Calcium Hydrogen Carbonate which gives shiny white finish.
15. Assertion: Food chain is responsible for the entry of harmful chemicals in our bodies.
Reason: The length and complexity of food chains vary greatly.
Assertion: Greater number of individuals are present in lower trophic levels.
Reason: The flow of energy is unidirectional.
16. Assertion: A geneticist crossed a pea plant having violet flowers with a pea plant with white flowers, he got all violet flowers in first generation.
Reason: White colour gene is not passed on to next generation.
Answer Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four subparts in these questions.
- Read the following and answer any four questions from 17 (i) to 17 (v).
All living cells require energy for various activities. This energy is available by the breakdown of simple carbohydrates either using oxygen or without using oxygen.
(i) Energy in the case of higher plants and animals is obtained by
b) Tissue respiration
c) Organ respiration
d) Digestion of food
(ii) The graph below represents the blood lactic acid concentration of an athlete during a race of 400 m and shows a peak at point D.
Lactic acid production has occurred in the athlete while running in the 400 m race. Which of the following processes explains this event?
a) Aerobic respiration
b) Anaerobic respiration
(iii) Study the graph below that represents the amount of energy supplied with respect to the time while an athlete is running at full speed.
Choose the correct combination of plots and justification provided in the following table.
(iv) The characteristic processes observed in anaerobic respiration are
i) presence of oxygen
ii) release of carbon dioxide
iii) release of energy
iv) release of lactic acid
a) i) ,ii) only
b) i), ii), iii) only
c) ii), iii), iv) only
d) iv) only
(v) Study the table below and select the row that has the incorrect information.
18. Read the following and answer any four questions from 18 (i) to 18 (v).
The ability of an atom to donate electrons and form positive ion (cation) is known as electropositivity or metallic character. Down the group, metallic character increases due to increase in atomic size and across the period, from left to right electropositivity decreases due to decrease in atomic size.
The ability of an atom to accept electrons to form a negative ion (anion) is called non-metallic character or electronegativity. The elements having high electro-negativity have a higher tendency to gain electrons and form anion. Down the group, electronegativity decreases due to increase in atomic size and across the period, from left to right electronegativity increases due to decrease in atomic size.
18 (i) Which of the following correctly represents the decreasing order of metallic character of Alkali metals plotted in the graph?
18 (ii) Hydrogen is placed along with Alkali metals in the modern periodic table though it shows non-metallic character
a) as Hydrogen has one electron & readily loses electron to form negative ion
b) as Hydrogen can easily lose one electron like alkali metals to form positive ion
c) as Hydrogen can gain one electron easily like Halogens to form negative ion
d) as Hydrogen shows the properties of non-metals
18 (iii) Which of the following has highest electronegativity?
18 (iv) Identify the reason for the gradual change in electronegativity in halogens down the group.
a) Electronegativity increases down the group due to decrease in atomic size
b) Electronegativity decreases down the group due to decrease in tendency to lose electrons
c) Electronegativity decreases down the group due to increase in atomic radius/ tendency to gain electron decreases
d) Electronegativity increases down the group due to increase in forces of attractions between nucleus & valence electrons
18 (v) Which of the following reason correctly justifies that “Fluorine (72pm) has smaller atomic radius than Lithium (152pm)”?
a) F and Li are in the same group. Atomic size increases down the group
b) F and Li are in the same period. Atomic size increases across the period due to increase in number of shells
c) F and Li are in the same group. Atomic size decreases down the group
d) F and Li are in the same period and across the period atomic size/radius decreases from left to right.
The complete sample paper and its marking scheme can be accessed from the links mentioned below: