Class 10 Science: CBSE (Official) Sample Question Paper (2020-21) | Science Class 10 PDF Download

 Page 1


 
1 
Sample Question Paper 2020-21 
Class X 
Science (086) Theory 
 
Time: 3 Hours                                                                         Maximum Marks: 80                                                                                                      
 
General Instructions: 
(i) The question paper comprises four sections A, B, C and D. There are 36 questions in 
the question paper. All questions are compulsory. 
(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. Answers to these should be given in 
one word or one sentence.  
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks 
each. Answers to these questions should in the range of 30 to 50 words. 
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks 
each. Answers to these questions should in the range of 50 to 80 words. 
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks 
each.  Answer to these questions should be in the range of 80 to 120 words. 
(vi) There is no overall choice. However, internal choices have been provided in some 
questions. A student has to attempt only one of the alternatives in such questions. 
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn. 
 
SECTION A 
No. Questions Marks 
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?   
OR 
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 
1g of Sodium metal? 
1 
2 Write the chemical name and chemical formula of the salt used to remove 
permanent hardness of water.  
1 
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 -CH
2
 and 14u molecular mass 
c) Gradation in physical properties 
d) Same functional group 
1 
4 Why does the Sun appear white at noon? 1 
Page 2


 
1 
Sample Question Paper 2020-21 
Class X 
Science (086) Theory 
 
Time: 3 Hours                                                                         Maximum Marks: 80                                                                                                      
 
General Instructions: 
(i) The question paper comprises four sections A, B, C and D. There are 36 questions in 
the question paper. All questions are compulsory. 
(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. Answers to these should be given in 
one word or one sentence.  
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks 
each. Answers to these questions should in the range of 30 to 50 words. 
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks 
each. Answers to these questions should in the range of 50 to 80 words. 
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks 
each.  Answer to these questions should be in the range of 80 to 120 words. 
(vi) There is no overall choice. However, internal choices have been provided in some 
questions. A student has to attempt only one of the alternatives in such questions. 
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn. 
 
SECTION A 
No. Questions Marks 
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?   
OR 
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 
1g of Sodium metal? 
1 
2 Write the chemical name and chemical formula of the salt used to remove 
permanent hardness of water.  
1 
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 -CH
2
 and 14u molecular mass 
c) Gradation in physical properties 
d) Same functional group 
1 
4 Why does the Sun appear white at noon? 1 
 
2 
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? 
1 
6 The image formed by a concave mirror is observed to be real, inverted and 
larger than the object. Where is the object placed? 
OR 
Name the part of a lens through which a ray of light passes without suffering 
any deviation. 
1 
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? 
1 
8 Draw the magnetic field lines around a straight current carrying conductor. 1 
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?  
OR 
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? 
1 
10 Veins are thin walled and have valves. Justify. 1 
11 How is the wall of small intestine adapted for performing the function of 
absorption of food? 
OR 
Out of a goat and a tiger, which one will have a longer small intestine? Justify 
your answer. 
1 
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. 
1 
Page 3


 
1 
Sample Question Paper 2020-21 
Class X 
Science (086) Theory 
 
Time: 3 Hours                                                                         Maximum Marks: 80                                                                                                      
 
General Instructions: 
(i) The question paper comprises four sections A, B, C and D. There are 36 questions in 
the question paper. All questions are compulsory. 
(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. Answers to these should be given in 
one word or one sentence.  
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks 
each. Answers to these questions should in the range of 30 to 50 words. 
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks 
each. Answers to these questions should in the range of 50 to 80 words. 
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks 
each.  Answer to these questions should be in the range of 80 to 120 words. 
(vi) There is no overall choice. However, internal choices have been provided in some 
questions. A student has to attempt only one of the alternatives in such questions. 
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn. 
 
SECTION A 
No. Questions Marks 
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?   
OR 
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 
1g of Sodium metal? 
1 
2 Write the chemical name and chemical formula of the salt used to remove 
permanent hardness of water.  
1 
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 -CH
2
 and 14u molecular mass 
c) Gradation in physical properties 
d) Same functional group 
1 
4 Why does the Sun appear white at noon? 1 
 
2 
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? 
1 
6 The image formed by a concave mirror is observed to be real, inverted and 
larger than the object. Where is the object placed? 
OR 
Name the part of a lens through which a ray of light passes without suffering 
any deviation. 
1 
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? 
1 
8 Draw the magnetic field lines around a straight current carrying conductor. 1 
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?  
OR 
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? 
1 
10 Veins are thin walled and have valves. Justify. 1 
11 How is the wall of small intestine adapted for performing the function of 
absorption of food? 
OR 
Out of a goat and a tiger, which one will have a longer small intestine? Justify 
your answer. 
1 
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. 
1 
 
3 
13 State the role of pancreas in digestion of food. 1 
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. 
1 
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. 
OR 
Assertion: Greater number of individuals are present in lower trophic levels. 
Reason: The flow of energy is unidirectional. 
1 
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. 
1 
 
Answer Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four sub-
parts in these questions. 
17 
 
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.  
1x4 
 (i) Energy in the case of higher plants and animals is obtained by  
a) Breathing  
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.  
 
Page 4


 
1 
Sample Question Paper 2020-21 
Class X 
Science (086) Theory 
 
Time: 3 Hours                                                                         Maximum Marks: 80                                                                                                      
 
General Instructions: 
(i) The question paper comprises four sections A, B, C and D. There are 36 questions in 
the question paper. All questions are compulsory. 
(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. Answers to these should be given in 
one word or one sentence.  
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks 
each. Answers to these questions should in the range of 30 to 50 words. 
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks 
each. Answers to these questions should in the range of 50 to 80 words. 
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks 
each.  Answer to these questions should be in the range of 80 to 120 words. 
(vi) There is no overall choice. However, internal choices have been provided in some 
questions. A student has to attempt only one of the alternatives in such questions. 
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn. 
 
SECTION A 
No. Questions Marks 
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?   
OR 
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 
1g of Sodium metal? 
1 
2 Write the chemical name and chemical formula of the salt used to remove 
permanent hardness of water.  
1 
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 -CH
2
 and 14u molecular mass 
c) Gradation in physical properties 
d) Same functional group 
1 
4 Why does the Sun appear white at noon? 1 
 
2 
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? 
1 
6 The image formed by a concave mirror is observed to be real, inverted and 
larger than the object. Where is the object placed? 
OR 
Name the part of a lens through which a ray of light passes without suffering 
any deviation. 
1 
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? 
1 
8 Draw the magnetic field lines around a straight current carrying conductor. 1 
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?  
OR 
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? 
1 
10 Veins are thin walled and have valves. Justify. 1 
11 How is the wall of small intestine adapted for performing the function of 
absorption of food? 
OR 
Out of a goat and a tiger, which one will have a longer small intestine? Justify 
your answer. 
1 
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. 
1 
 
3 
13 State the role of pancreas in digestion of food. 1 
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. 
1 
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. 
OR 
Assertion: Greater number of individuals are present in lower trophic levels. 
Reason: The flow of energy is unidirectional. 
1 
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. 
1 
 
Answer Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four sub-
parts in these questions. 
17 
 
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.  
1x4 
 (i) Energy in the case of higher plants and animals is obtained by  
a) Breathing  
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.  
 
 
4 
 
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  
c) Fermentation  
d) Breathing 
 (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. 
 
 
Page 5


 
1 
Sample Question Paper 2020-21 
Class X 
Science (086) Theory 
 
Time: 3 Hours                                                                         Maximum Marks: 80                                                                                                      
 
General Instructions: 
(i) The question paper comprises four sections A, B, C and D. There are 36 questions in 
the question paper. All questions are compulsory. 
(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. Answers to these should be given in 
one word or one sentence.  
(iii) Section–B - question no. 21 to 26 are short answer type questions, carrying 2 marks 
each. Answers to these questions should in the range of 30 to 50 words. 
(iv) Section–C - question no. 27 to 33 are short answer type questions, carrying 3 marks 
each. Answers to these questions should in the range of 50 to 80 words. 
(v) Section–D – question no. - 34 to 36 are long answer type questions carrying 5 marks 
each.  Answer to these questions should be in the range of 80 to 120 words. 
(vi) There is no overall choice. However, internal choices have been provided in some 
questions. A student has to attempt only one of the alternatives in such questions. 
(vii) Wherever necessary, neat and properly labeled diagrams should be drawn. 
 
SECTION A 
No. Questions Marks 
1 List any two observations when Ferrous Sulphate is heated in a dry test tube?   
OR 
Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 
1g of Sodium metal? 
1 
2 Write the chemical name and chemical formula of the salt used to remove 
permanent hardness of water.  
1 
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 -CH
2
 and 14u molecular mass 
c) Gradation in physical properties 
d) Same functional group 
1 
4 Why does the Sun appear white at noon? 1 
 
2 
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? 
1 
6 The image formed by a concave mirror is observed to be real, inverted and 
larger than the object. Where is the object placed? 
OR 
Name the part of a lens through which a ray of light passes without suffering 
any deviation. 
1 
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? 
1 
8 Draw the magnetic field lines around a straight current carrying conductor. 1 
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?  
OR 
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? 
1 
10 Veins are thin walled and have valves. Justify. 1 
11 How is the wall of small intestine adapted for performing the function of 
absorption of food? 
OR 
Out of a goat and a tiger, which one will have a longer small intestine? Justify 
your answer. 
1 
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. 
1 
 
3 
13 State the role of pancreas in digestion of food. 1 
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. 
1 
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. 
OR 
Assertion: Greater number of individuals are present in lower trophic levels. 
Reason: The flow of energy is unidirectional. 
1 
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. 
1 
 
Answer Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four sub-
parts in these questions. 
17 
 
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.  
1x4 
 (i) Energy in the case of higher plants and animals is obtained by  
a) Breathing  
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.  
 
 
4 
 
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  
c) Fermentation  
d) Breathing 
 (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. 
 
 
 
5 
 Plot A Plot B Justification  
a) Aerobic  Anaerobic  Amount of energy is low and inconsistent  
in aerobic and high  in anaerobic 
b) Aerobic  Anaerobic Amount of energy is high and consistent  
in aerobic and low in anaerobic 
c) Anaerobic  Aerobic  Amount of energy is high and consistent  
in aerobic and low in anaerobic 
d) Anaerobic  Aerobic  Amount of energy is high and inconsistent  
in anaerobic and low in aerobic 
 
 (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. 
 
  Aerobic  Anaerobic  
a) Location  Cytoplasm  Mitochondria  
b) End Product  CO
2
 and H
2
0  Ethanol and CO
2
 
c) Amount of ATP  High  Low 
d) Oxygen  Needed  Not needed 
 
 
18 Read the following and answer any four questions from 18 (i) to 18 (v). 
Metallic Character 
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 
 
 
1x 4