CBSE Class 10 Science Answer key 2024

The CBSE Class 10 Science exam is an important milestone for students, testing their understanding of scientific concepts and principles. After the exam, students eagerly await the release of the answer key to check their answers and assess their performance. In this blog, we will provide an analysis of the CBSE Class 10 Science answer key 2024 for sets 1, 2, and 3.

Also Check: CBSE Class 10 Science Paper Analysis

CBSE Class 10 Science Paper

The CBSE Class 10 Science Paper will be held on March 2, 2024, from 10:30 am to 1:30 pm. The question paper will consist of Competency-based questions, MCQ Type Questions and Short & Long Answer Type Questions, for a total of 80 marks.

CBSE Class 10 Science Answer Key

The CBSE Class 10 Science answer key is a document that contains the correct answers to the questions asked in the Class 10 Science exam. It is released by various coaching institutes and educational websites shortly after the exam is conducted. The answer key helps students check their answers and evaluate their performance in the exam. By comparing their answers with the answer key, students can estimate their scores and identify any mistakes they may have made. This can help them understand their strengths and weaknesses and improve their performance in future exams.

CBSE Class 10 Science Answer Key for Set 1, 2 & 3

The CBSE Class 10 Science answer key 2024 for sets 1, 2, and 3 provides a detailed analysis of the exam paper. It includes the following key points:

1. Difficulty Level: The answer key indicates the overall difficulty level of the exam. It helps students understand the complexity of the questions and their preparedness.
2. Topic-wise Analysis: The answer key breaks down the questions according to the topics covered in the syllabus. This analysis helps students identify their strengths and weaknesses in each subject.
3. Expected Cutoff: Based on the analysis of the answer key, experts predict the expected cutoff marks for the exam. This information is crucial for students to gauge their chances of qualifying for the next stage of the selection process.

CBSE Class 10 Science Answer Key for Set 1, 2 & 3 – Paper Analysis

The CBSE Class 10 Science Exam 2023 was conducted smoothly by the Central Board of Secondary Education today. The exam, which lasted for three hours, took place in a single shift from 9:30 AM to 12:30 PM.

The Class 10 Science question paper consisted of a mix of average and moderately easy questions. Every question followed the syllabus, with the textbook serving as the source for approximately 70–80% of the questions.

Students found the paper manageable and were able to complete it comfortably within the allotted time. The questions were well-distributed, covering areas such as knowledge, application, evaluation, and other skills. The multiple-choice questions (MCQs) were straightforward and of moderate difficulty.

The paper included case-based questions that were evenly spread throughout and varied in difficulty from easy to moderate. Overall, the exam was fair and balanced, providing students with a chance to showcase their understanding and skills.

 

CBSE Class 10 Science Answer Key Set 1, 2, 3

Here we have provided the answer key for CBSE Class 10 Science Answer Key 2024 Set 1. Candidates who got the Class 10 Science Set 1,2,3 Question Paper can cross-check their Answers with the Class 10 Science Answer Key 2024 .

CBSE Class 10 Science Paper 2024 with Answers Keys for Set 1

1. The colour of the solution observed after 30 minutes of placing zinc metal to copper sulphate solution is
a) Blue
b) Colourless
c) Dirty green
d) Reddish Brown

Answer: b) Colourless

2. Mild non-corrosive basic salt is
a) Ca (OH)2
b) NaCl
c) NaOH
d) NaHCO3

Answer: NaHCO3

3. On adding dilute sulphuric acid to a test tube containing a metal „X‟, a colourless gas is produced when a burning match stick is brought near it. Which of the following correctly represents metal „X‟?
a) Sodium
b) Zinc
c) Copper
d) Silver

Answer: Sodium

4. An element with atomic number_____ will form a basic oxide.
a) 7 (2,5)
b) 17 (2,8,7)
c) 14 (2,8,4)
d) 11 (2,8,1)

Answer: d) 11 (2,8,1)

5. An element „M’ has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of „M‟ is:
a) 10
b) 12
c) 14
d) 18

Answer:c) 14

6. Generally food is broken and absorbed within the body of organisms. In which of the following organisms is it done outside the body?
a) Amoeba
b) Mushroom
c) Paramoecium
d) Lice

Answer: b) Mushroom

7. Receptors are usually located in sense organs. Gustatory receptors are present in
a) tongue
b) nose
c) eye
d) ear

Answer: a) tongue

8. A farmer wants to grow banana plants genetically similar enough to the plants already available in his field. Which one of the following methods would you suggest for this purpose?

a) Regeneration
b) Budding
c) Vegetative propagation
d) Sexual reproduction

Answer:c) Vegetative propagation

9. Height of a plant is regulated by:

a) DNA which is directly influenced by growth hormone.
b) Genes which regulate the proteins directly.
c) Growth hormones under the influence of the enzymes coded by a gene.
d) Growth hormones directly under the influence a gene.

Answer:c) Growth hormones under the influence of the enzymes coded by a gene.

10. A sportsman, after a long break of his routine exercise, suffered muscular cramps during a heavy exercise session. This happened due to:
a) lack of carbon dioxide and formation of pyruvate.
b) presence of oxygen and formation of ethanol.
c) lack of oxygen and formation of lactic acid.
d) lack of oxygen and formation of carbon dioxide.

Answer: c) lack of oxygen and formation of lactic acid.

11. An object is placed in front of a convex mirror. Its image is formed :

a) at a distance equal to the object distance in front of the mirror.
b) at twice the distance of the object in front of the mirror.
c) half the distance of the object in front of the mirror.
d) behind the mirror and its position varies according to the object distance.

Answer:d) behind the mirror and its position varies according to the object distance.

12. When light enters the atmosphere it strikes on extremely fine particles, which deflect the rays of light in all possible directions, This is due to –
a) reflection of light
b) atmospheric refraction
c) scattering of light

d) dispersion of light

Answer:c) scattering of light

13. In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of “X” to prevent depletion of “Y”. “X” and “Y” respectively referred here are:
a) Ozone; CFCs
b) CFCs; rays UV
c) CFCs; Ozone
d) UV rays; Diatomic oxygen

Answer: CFCs, Ozone

14. Which of the following features relates to biodegradable substances?
a) Broken down by biological processes
b) Remain inert
c) Persist in environment for a long time
d) May harm the ecosystem

Answer: a) Broken down by biological processes

CBSE Class 10 Science Paper 2024 with Answers Keys for Set 2

Question No. 15 to 18 consist of two statements – Assertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below:

a) Both A and R are true, and R is the correct explanation of A.
b) Both A and R are true, and R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true.

15. Assertion: Rusting of Iron is endothermic in nature.
Reason: As the reaction is slow, the release of heat is barely evident.

Answer: d) Assertion is false but Reason is true

16. Assertion: Probability of survival of an organism produced through sexual reproduction is more than that of organism produced through asexual mode.
Reason: Variations provide advantages to individuals for survival.

Answer: a) Both A and R are true and R is the correct explanation of A.

17. Assertion: A compass needle is placed near a current-carrying wire. The deflection of the compass needle decreases when the magnitude of the current in the wire is increased.
Reason: The strength of a magnetic field at a point near the conductor increases on increasing the current.

Answer:d) Assertion is false but Reason is true

18. Assertion: Biodegradable substances result in the formation of compost and natural replenishment.
Reason: It is due to the breakdown of complex inorganic substances into simple organic substances.

Answer:c) A is true but R is false.

CBSE Class 10 Science Paper 2024 with Answers Keys for Set 3

Select from the following the conditions responsible for the rapid spread of bread mould on a slice of bread:
(i) Formation of large number of spores
(ii) Presence of moisture and nutrients in bread
(iii) Low Temperature
(iv) Presence of Hyphae

(A) (i) and (ii)
(B) (ii) and (iv)
(C) (ii) and (iii)
(D) (iii) and (iv)

Answer: (A) (i) and (ii)

2. The incorrect statement about placenta is :
(A) It is a disc embedded in the uterine wall.
(B) It contains villi on the embryo’s side of the tissue.
(C) It has a very small surface area for glucose and oxygen to pass from mother to the embryo.
(D) The embryo gets nutrition from the mother’s blood through it.

Answer: (C) It has a very small surface area for glucose and oxygen to pass from mother to the embryo.

3. An aqueous solution ‘A’ turns phenolphthalein solution pink. When another aqueous solution ‘B’ is added to the pink solution, the pink colour disappears. Now when a few drops of solution ‘A’ are added to this reaction, the mixture appears pink again. The respective changes in the nature of the solution are from :
(A) acidic → basic → basic

(B) basic → acidic → acidic

(C) acidic → basic → acidic

(D) basic → acidic → basic

Answer: (D) basic → acidic → basic

4. The correct sequence of events when someone’s hand touches a hot object unconsciously :
(A) Receptors in skin → Motor neuron → Relay neuron → Sensory neuron → Effector muscle in arm
(B) Receptors in skin → Relay neuron → Sensory neuron → Motor neuron → Effector muscle in arm
(C) Receptors in skin → Sensory neuron → Relay neuron → Motor neuron → Effector muscle in arm
(D)Receptors in skin → Sensory neuron → Effector muscle in arm → Motor neuron → Relay neuron

Answer: (C) Receptors in skin → Sensory neuron → Relay neuron → Motor neuron → Effector muscle in arm

5. To balance the following chemical equation, the values of the coefficients x, y and & must be respectively :
Zn(NO3)2 A → y ZnO + z NO2 + O2
(A) 4, 2, 2
(B) 2, 2, 4
(C) 4, 4, 2
(D) 2, 4, 2

6. Which of the following is a redox reaction, but not a combination reaction?
(A) C+ O2→CO2
(B) 2 Mg + O2 → 2 MgO
(C) 2H2 + O2→2 H2O
(D) Fe2O3+ 3CO → 2 Fe + 3CO2

Answer: (A) C+ O2→CO2

7. An aqueous solution of sodium chloride is prepared in distilled water. The pH of this solution is:

(A) 6

(B) 8

(С) 7

(D) 3

Answer: (С) 7

8. A metal X’ is used in thermit process. When X’ is heated with oxygen, it gives an oxide Y, which is amphoteric in nature. X’ and Y respectively are :
(A) Mn, MnO2
(C) Fe, Fe2O3
(B) Al, Al2O3
(D) Mg, MgO

Answer: (B) Al, Al2O3

9. The process in which transport of soluble products of photosynthesis takes place in plants is known as :

(A)Transpiration
(C) Conduction
(B) Evaporation
(D) Translocation

Answer: (D) Translocation

10. Sense organ in which olfactory receptors are present is
(A) Nose
(B) Skin
(C)Tongue
(D)Inner ear

Answer: (A) Nose

15. The colour of light for which the refractive index of glass is minimum, is:
(A) Red
(B) Yellow
(C)Green
(D) Violet

Answer: (A) Red

16. The current carrying device which produces a magnetic field similar to that of a bar magnet is :
(A) A straight conductor
(B) A circular loop
(C) A solenoid
(D) A circular coil

Answer: (C) A solenoid

For Questions number 17 to 20, two statements are given — one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below.
(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.

17. Assertion (A) : Electrons move from lower potential to higher potential in a conductor.
Reason (R) : A dry cell maintains electric potential difference across the ends of a conductor.

Answer: (D) Assertion (A) is false, but Reason (R) is true.

18. Assertion (A) : Some vegetable oils are healthy.
Reason (R): Vegetable oils generally have long unsaturated carbon chains.

Answer: (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

19. Assertion (A): Sex of the children will be determined by what they inherit from their mother.
Reason (R): Women have XX sex chromosomes.

Answer: (C) Assertion (A) is true, but Reason (R) is false.

20. Assertion (A): Green plants trap only 1% of the energy of sunlight that falls on their leaves.
Reason (R) : All green plants are the producers in a food chain.

Answer: (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

Questions no. 21 to 26 are very short answer type questions.
21. (a) Sometimes while running, the athletes suffer from muscle cramps. Why? How is the respiration in this case different from aerobic respiration?
OR (b) Write the other name given to lymph. State its two functions.

22. Write the formula and the molecular mass of the third homologue of alcohols. State how the boiling point of an alcohol changes as one moves from lower to higher homologues.

23. (a) Copper powder is taken in a china dish and heated over a burner. Name the product formed and state its colour. Write the chemical equation for the reaction involved.
OR (b) Write chemical equation for the chemical reaction which occurs when the aqueous solutions of barium chloride and sodium sulphate react together. Write the symbols of the ions present in the compound precipitated in the reaction.

24. Identify the organ in the human female reproductive system where the sperm encounters the egg cell. What will happen if it is blocked ? Name the technique by which it can be blocked.

25. The linear magnification produced by a spherical mirror is +3.” Based on this statement answer the following questions :
(a) What is the type of mirror?
(b) Where is the object located ?
(c) List two properties of the image formed (other than the size/magnification).

26. The filament of an electric lamp draws a current of 0•5 A, which lights for 2 hours. Calculate the charge that flows through the circuit.

27. Answer the following questions in the context of electrolysis of water :
(a) Why is this reaction/process called a decomposition reaction?
(b) Giving reason state whether this reaction is exothermic or endothermic.
(c) Name the gases collected at the anode and cathode.
(d) What is the mass ratio of the gases collected at the anode and cathode ?

28. Differentiate between food chain and food web. In a food chain consisting of deer, grass and tiger, if the population of deer decreases, what will happen to the population of organisms belonging to the first and third trophic levels?

29. Name a plant growth hormone synthesized at the shoot tip. Explain its effect on the growth of a plant in response to light.

30. Name the ore of mercury and state the form in which it is found in nature. Write the chemical equations along with the condition required for the reactions involved in the extraction of mercury from its ore.

31. Mendel crossed pure tall pea plants (TT) with pure short pea plants (tt) and obtained F, progeny. When the plants of F, progeny were self-pollinated, plants of F2 progeny were obtained.

(a) What did the plants of F1 progeny look like? Give their gene combination.
(b) Why could the gene for shortness not be expressed in plants of Fi progeny?
(c) Write the ratio of the plants obtained in F2 progeny and state the conclusion that can be drawn from this experiment.