Science Previous Year Questions (PYQs) Class 10 – A Complete

Science is a subject that students often find intriguing and challenging, especially when preparing for exams. Class 10 science covers various concepts in Physics, Chemistry, and Biology, which are essential for understanding the world around us. One of the most effective ways to prepare for exams is by solving previous year questions (PYQs). These questions help you understand the exam pattern, important topics, and the type of questions likely to appear in your exams. This article provides a comprehensive collection of PYQs for Class 10 Science, covering all three major subjects.

In addition to the questions and answers, this article will also guide you through the importance of these PYQs and how they can help you enhance your exam preparation. Additionally, we will provide book recommendations for further reading.

Before diving into the questions and answers, let’s discuss why solving PYQs is crucial for Class 10 students:

1. Understand the Exam Pattern: PYQs give you insight into the types of questions that are often asked. This helps you become familiar with the format and the level of difficulty.
2. Identify Important Topics: By analyzing past years’ questions, you can identify frequently asked topics, which you should prioritize during your preparation.
3. Boost Confidence: Solving previous year questions will give you a confidence boost, as you will feel more prepared for the actual exam.
4. Improve Time Management: Practice with PYQs helps you get a better understanding of time management. You can solve questions within the given time frame and identify the areas where you need improvement.

Science PYQs for Class 10 – Physics

Physics in Class 10 deals with fundamental concepts such as motion, force, light, electricity, and magnetism. Here are 10 important Physics PYQs:

1. What is the difference between speed and velocity?

Answer: Speed is a scalar quantity that refers to how fast an object is moving, while velocity is a vector quantity that includes both the speed and direction of an object.

2. State Newton’s Second Law of Motion.

Answer: Newton’s Second Law of Motion states that the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to its mass. Mathematically, $F=ma$.

3. What is the formula for calculating the power of an electrical appliance?

Answer: Power is the rate at which work is done. The formula for power is:
P=WtP = \frac{W}{t}P=tW​
Where $P$ is power, $W$ is work, and $t$ is time.

4. What is Ohm’s Law?

Answer: Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance. The formula is:
$V=IR$

5. What is refraction of light?

Answer: Refraction is the bending of light when it passes from one medium to another with a different density. This change in speed results in the bending of light.

6. What is the formula for calculating the work done by a force?

Answer: The formula for work done is:
$W=F\times d$
Where $W$ is work, $F$ is the force, and $d$ is the distance moved in the direction of the force.

7. What is the difference between parallel and series combinations of resistors?

Answer: In a series combination, the current is the same through all resistors, while in a parallel combination, the voltage across each resistor is the same.

8. What are the laws of reflection?

Answer: The laws of reflection are:

• The angle of incidence is equal to the angle of reflection.
• The incident ray, the reflected ray, and the normal lie in the same plane.

9. What is an electromagnet?

Answer: An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The strength of the electromagnet can be increased by increasing the current or wrapping the wire into coils.

10. What is the working principle of a transformer?

Answer: A transformer works on the principle of electromagnetic induction. It increases or decreases the voltage of alternating current (AC) through a set of coils.

Science PYQs for Class 10 – Chemistry

Chemistry in Class 10 covers topics such as acids, bases, salts, chemical reactions, and more. Here are 10 important Chemistry PYQs:

11. What is the pH scale?

Answer: The pH scale measures how acidic or basic a substance is. A pH of 7 indicates neutrality, below 7 indicates acidity, and above 7 indicates basicity.

12. What is a chemical reaction? Provide an example.

Answer: A chemical reaction involves the rearrangement of atoms to form new substances. For example, when zinc reacts with hydrochloric acid, zinc chloride and hydrogen gas are formed.

13. What is an exothermic reaction?

Answer: An exothermic reaction is one that releases energy in the form of heat. For example, the combustion of fuel is an exothermic reaction.

14. What is an electrolyte?

Answer: An electrolyte is a substance that conducts electricity when dissolved in water or melted, such as salts, acids, and bases.

15. What is the law of conservation of mass?

Answer: The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction, it only changes form.

16. Write the balanced equation for the reaction between sodium and water.

Answer:
2Na+2H2O→2NaOH+H22Na + 2H_2O \rightarrow 2NaOH + H_22Na+2H2​O→2NaOH+H2​

17. What is the difference between endothermic and exothermic reactions?

Answer: Endothermic reactions absorb energy, while exothermic reactions release energy.

18. What are acids and bases? Give examples.

Answer: Acids are substances that donate protons (H+) in a reaction, e.g., hydrochloric acid (HCl). Bases are substances that accept protons, e.g., sodium hydroxide (NaOH).

19. What is an alloy? Give examples.

Answer: An alloy is a mixture of two or more metals. Examples include brass (copper and zinc) and steel (iron and carbon).

20. What is the difference between ionic and covalent bonds?

Answer: Ionic bonds form when electrons are transferred from one atom to another, while covalent bonds form when electrons are shared between atoms.

Science PYQs for Class 10 – Biology

Biology in Class 10 covers the study of living organisms, their structures, functions, and processes. Here are 10 important Biology PYQs:

21. What is the role of the human respiratory system?

Answer: The respiratory system facilitates the exchange of gases, where oxygen is taken in and carbon dioxide is expelled from the body.

22. What is photosynthesis?

Answer: Photosynthesis is the process by which green plants use sunlight, carbon dioxide, and water to produce glucose and oxygen.

23. What is the function of the heart?

Answer: The heart pumps blood throughout the body, delivering oxygen and nutrients to tissues and removing waste products.

24. What are the parts of the human digestive system?

Answer: The human digestive system consists of the mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas.

25. What is the process of reproduction in humans?

Answer: Human reproduction involves the fusion of male and female gametes (sperm and egg) to form a zygote, which develops into a fetus.

26. What is the function of white blood cells?

Answer: White blood cells are part of the immune system and help protect the body against infections and foreign invaders.

27. What is the role of the kidney in excretion?

Answer: The kidney filters waste products from the blood and excretes them in the form of urine.

28. What is the difference between aerobic and anaerobic respiration?

Answer: Aerobic respiration requires oxygen to produce energy, while anaerobic respiration occurs without oxygen, producing less energy.

29. What is the role of hormones in the human body?

Answer: Hormones are chemical messengers that regulate various physiological processes, including growth, metabolism, and reproduction.

30. What is the significance of biodiversity?

Answer: Biodiversity refers to the variety of life forms on Earth. It is crucial for ecosystem stability, food security, and medicinal resources.

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Recommended Books for Class 10 Science Exam Preparation

To enhance your understanding of the topics and practice more PYQs, here are some recommended books:

1. NCERT Science Textbook for Class 10 – The official textbook by NCERT is the best resource for Class 10 Science students.
2. Trueman’s Elementary Biology – A comprehensive book for Biology with detailed explanations and practice questions.
3. H.C. Verma’s Concepts of Physics – This book is highly recommended for Physics as it covers the concepts in-depth and provides excellent problems for practice.
4. Modern’s ABC of Chemistry – A useful book for Chemistry students, which contains all the important topics with clear explanations.
5. Oswal Publishers’ Class 10 Science PYQs – A collection of previous year questions for practice.

Solving PYQs is a vital part of preparing for the Class 10 Science exams. It not only helps you get familiar with the exam format but also strengthens your understanding of key concepts. The above 50 questions, spanning Physics, Chemistry, and Biology, will provide you with a solid foundation for your preparation. By practicing these questions and referring to the suggested books, you can enhance your chances of performing well in the exams.