CBSE Class 10th Science Important Questions (Chapter Wise) PDF Download

CBSE Class 10th Science important questions are crucial for students to improve their understanding. It's especially important for those preparing for the CBSE 10th board exam. This article is designed to help students thoroughly grasp the important questions for CBSE Class 10th Science.

The CBSE 10th board exam board exams include both practical and theory tests. A collection of important questions from all topics has been compiled by analysing previous year's question papers.

CBSE Class 10th Science Important Questions Free PDF Download

Classroom sessions generally don't cover all the critical questions the students must focus on while preparing for board examinations. A comprehensive list of questions would do wonders for the students to score well in the examination. You can download chapter-wise important questions for CBSE class 10 from the PDF files provided below.

Read More: CBSE Additional Practice Papers

CBSE Class 10 Science Most Repeated Questions

The table below contains the most repeated questions in the CBSE Class 10 Science exam. These questions have been bifurcated as per the mark allocation.

1 Mark Questions

1. Which of these is true about how light reflects off surfaces?

• (a) It only works for flat (plane) mirrors.

• (b) It only works for mirrors that curve inward (concave).

• (c) It only works for mirrors that curve outward (convex).

• (d) It works for all types of reflecting surfaces.

2. Two light bulbs (100 W and 40 W) are joined together in a single line (series). If 1 A of current flows through the 100 W bulb, how much current flows through the 40 W bulb?

• (a) 0.4 A

• (b) 0.6 A

• (c) 0.8 A

• (d) 1 A

3. If you place an object very close to a concave mirror (inside its focal point), the image appears larger and looks like it is behind the mirror. This image is:

• (a) Real

• (b) Upside down (inverted)

• (c) Fake (virtual) and upside down

• (d) Fake (virtual) and right-side up (erect)

4. Decide if these two statements are true and if the second one explains the first:

• Statement (A): Metals and alloys allow electricity to flow through them easily.

• Reason (R): Bronze is a mix of copper and tin, and it does not conduct electricity well.

• (a) Both are true, and R explains A.

• (b) Both are true, but R does not explain A.

• (c) A is true, but R is false.

• (d) A is false, but R is true.

5. Decide if these two statements are true and if the second one explains the first:

• Statement (A): We use alloys (metal mixtures) in things like heaters and irons.

• Reason (R): Alloys resist electricity more than pure metals, but they melt at lower temperatures than pure metals.

• (a) Both are true, and R explains A.

• (b) Both are true, but R does not explain A.

• (c) A is true, but R is false

• (d) A is false, but R is true.

2 Mark Questions

1. Explain the different ways plants get rid of their waste products.
   
   
2. Compare saprophytic nutrition (eating dead stuff) and parasitic nutrition (feeding off a living host). Focus on what they eat and how they get it.
   
   
3. Why is Bile juice important if it doesn't even have enzymes? Even though bile doesn't "digest" food as enzymes do, why are bile salts necessary for the body to handle fats?
   
   
4. Trace the step-by-step path (the reflex arc) that your nerves take from the moment a bright light hits your eyes to the moment your muscles react.
   
   
5. In pea plants, what does it mean to have a "dominant height"? Explain what a dominant trait is regarding how tall a pea plant grows, and give two examples of dominant traits in these plants.
   
   
6. What is the magnification of a standard plane mirror, and why is it that specific number?
   
   
7. Draw a labelled diagram showing what happens when a ray of light, travelling parallel to the centre line (principal axis), hits a convex mirror. Be sure to mark the angles where the light hits and bounces off.
   
   
8. Describe the image in this mirror setup: An object is placed 12 cm away from a concave mirror that has a radius of 30 cm. List four specific things about the image that is formed.
   
   
9. Why does water electrolysis produce more of one gas than the other? When you use electricity to split water, why do you get twice as much gas at one end compared to the other?
   
   
10. Out of Copper, Lead, Magnesium, and Silver, which one can take the place of Zinc in a chemical solution? Explain why using a chemical equation.

3 Mark Questions

1. A spherical mirror produces a magnification of +3. Based on this number, identify the type of mirror and where the object is located relative to it. Draw a ray diagram to show how the image is formed.
   
   
2. Explain the specific reasoning behind the following statements:
   a. Skills or traits acquired during a person's lifetime are not passed down to their children.
   b. Despite different appearances, all humans belong to a single species.
   c. Small variations accumulate during reproduction and persist in future generations.
   
   
3. Why are the following specific materials used for these purposes?
   a. Graphite for making electrodes.
   b. PVC or rubber for coating electric wires.
   c. Metal alloys for making bells and musical instrument strings.
   
   
4. Draw a schematic diagram showing the different pathways by which a glucose molecule breaks down to release energy.
   
   
5. Draw ray diagrams to show the path of a light ray in the following situations:
   (i) It passes through the centre of curvature of a concave mirror.
   (ii) It travels parallel to the principal axis and strikes a convex mirror.
   (iii) It passes through the focus of a concave mirror.
   
   
6. Name the hormones produced by the following glands and list one major function for each:
   a. Thyroid
   b. Pituitary
   c. Pancreas
   
   
7. Describe what happens to a glucose molecule during:
   a. Anaerobic respiration (in Yeast and Lactobacillus bacteria).
   b. Aerobic respiration (in human cells).
   
   
8. Please write the chemical equation for each process.
   
   
9. What is the main function of an electric fuse? What material is used to make the fuse wire, and why is that specific material chosen?
   
   
10. "It is purely a matter of chance whether a couple will have a boy or a girl." Justify this statement by drawing a flow chart.
    
    
11. An ore bubbles rapidly (brisk effervescence) when treated with dilute hydrochloric acid.
    a. What type of ore is this? What steps are needed to extract metal from it?
    b. If a copper coin is dipped into a silver nitrate solution, what happens to the coin and the colour of the solution? Write the balanced chemical equation for this reaction.
    
    
12. Two electric lamps are connected in parallel to a 220 V main supply. One is rated 100 W; 220 V, and the other is 60 W; 220 V. Calculate the total current drawn by these two bulbs.
    
    
13. What is DNA copying, and why is it considered important?
    
    
14. During the electrolysis of water:
    a. Which gas is collected at the cathode and which at the anode?
    b. Why is the volume of gas collected at one electrode double the volume at the other? Name this gas.
    c. How would you test for this gas?
    
    
15. What are the main differences between Photosynthesis and Respiration?

5 Mark Questions

1. Identify the specific metal or non-metal corresponding to each description below:
   a. The element added to iron to enhance its hardness and tensile strength.
   b. The metal alloyed with other elements to form an amalgam.
   c. The metal utilized in the galvanization process to protect iron articles.
   d. The metal that develops a black corrosion layer when exposed to atmospheric air.
   
   
2. A specific metal, designated as element 'E', is stored under kerosene. When exposed to air, it ignites spontaneously. The product of this combustion forms a basic solution that turns red litmus blue when dissolved in water.
   a. Identify element 'E'.
   b. Write the balanced chemical equations for:
   (i) The reaction of 'E' with air.
   (ii) The dissolution of the resulting product in water.
   
   
3. Provide scientific justification for the following observations:
   a. Carbonate and sulphide ores are typically converted into oxides before the reduction process in metallurgy.
   b. Ionic compounds characteristically exhibit high melting points.
   c. Hydrogen is included in the metal reactivity series despite being a non-metal.
   d. Iron articles remain protected from rusting even if their galvanised zinc coating is compromised.
   
   
4. a. Define the biological process of excretion.
   b. Identify the fundamental filtration unit located within the kidney.
   c. Draw a schematic of the human excretory system and label the specific organs responsible for the following functions:
   (i) The formation of urine.
   (ii) The transport of urine from the kidneys.
   (iii) The storage of urine prior to micturition (elimination).
   
   
5. A candle flame is placed 30 cm in front of a spherical mirror. Its distinct image is captured on a screen positioned 60 cm from the mirror's pole.
   a. Identify the nature of the mirror and calculate its focal length.
   b. Given a flame height of 2.4 cm, calculate the height of the formed image.
   c. State whether the image is erect or inverted.
   
   
6. A mirror produces a real, inverted image with a magnification of -1. The image is located 40 cm from the mirror.
   a. Determine the initial position of the object.
   b. If the object is subsequently moved 20 cm towards the mirror, determine the new position of the image.
   c. Provide a rationale for your calculation and draw a ray diagram corresponding to the object's new position.

CBSE Class 10th Science Syllabus and Marks Distribution

You must be aware of the marking scheme for all the topics that CBSE decides for the 10th Science Board examination. This will help you prepare for your examinations effectively.

CBSE Class 10th Science Exam Pattern 

Other than Important Questions for CBSE Class 10 Science, it is also important for you to understand that the CBSE Class 10th Science paper is split into three sections, A, B, and C. All of these sections are mandatory for you to attempt. The following table explains the CBSE Class 10th Science exam pattern for the current academic year.

Read More: CBSE 10th Date Sheet 2026

Since you have no overall choice, internal options have been provided within all three sections of the Class 10th Science paper. This includes a weightage of 33%. The pattern followed is often seen within the sample papers that CBSE has provided. You can also refer to the table given below to understand the assessment areas for the theoretical Science board examination.

CBSE Class 10th Science Internal Assessment

The table below provides the students with an idea of the breakup of internal assessment for subject enrichment and portfolio, and the marks allocation for the same.