CBSE Class 10 – Board Exam Mathematics Paper Writing & Time-Management Tips

1. Use the 15-Minute Reading Time Smartly

Go through the entire question paper once calmly — do NOT start solving mentally in panic.

Identify very easy MCQs → answers should be ready in your mind.

For longer questions, quickly think of the method/logic you will use (quadratic, AP formula, similarity, trigonometry etc.).

In optional questions, immediately decide which question you will attempt. Do not waste time later deciding.

2. Time Management Strategy

Thumb rule: 2 minutes per 1 mark

1 mark → ~2 minutes

2 marks → ~4 minutes

3 marks → ~6 minutes

5 marks → ~10 minutes

Try to finish Section A (MCQs) within 25–30 minutes.

If an MCQ is taking time, skip it and return at the end — do not get stuck early in the paper.

Attempt the paper in this order for confidence:MCQ → 2/3-mark questions → 4/5-mark questions → revisit difficult ones

3. Presentation (Very Important in Maths)

Always start word problems with:Given :To Find :

Write the formula first, then substitute values.

Show complete steps — every step carries marks.

Avoid solving entirely in rough work; write properly in the answer sheet.

4. Geometry

Draw neat, labelled diagrams using pencil and scale.

Mention the theorem used (e.g., BPT, Pythagoras, Tangent theorem).

Write proper statements such as:“In ΔABC and ΔDEF”“Since DE ∥ BC…”

5. Calculation & Accuracy

Keep calculations clean and aligned.

Box the final answer clearly.

Write correct units (cm, m², cm³, etc.).

Use π = 22/7 unless the question states otherwise.

6. Common Mistakes to Avoid

Do not skip steps in quadratic equations and trigonometry identities.

Do not forget negative sign while solving linear equations.

Do not write only answers in 2–5 mark questions — method marks are very important.

Even in case of case-study questions, a complete solution with proper steps is a must.

7. Last 20 Minutes Checklist

Recheck all MCQs.

Verify calculations (especially Surface Areas & Volumes and Statistics).

Check units and diagrams.

Ensure no question is left unattempted.

All the best!

CBSE Class 10 | Mathematics | Some important tips for the board exam preparation

1. Ensure that you have solved each and every question both – exercise questions and the solved examples from NCERT.
2. Ensure that you have memorised all the required formulae. 
3. Ensure that you are thorough with the proofs of the geometry theorems. 
4. Ensure that you remember the values of trigonometric ratios (0°, 30°, 45°, 60°, 90°). 
5. Check the previous year questions should be solved. It gives you a better idea about the kinds of questions asked in the exam.

A detailed list of chapters and formulae:

• Polynomials – 
• Relationship between the zeroes and the coefficients 
• Quadratic equations – 
• Formula for finding the roots
• Arithmetic progression – 
• Finding the nth term an 
• Sum of the first nth terms Sn
• Co-ordinate geometry – 
• Distance formula
• Section formula
• Mid-point formula
• Introduction to trigonometry – 
• Trigonometric identities 
• Areas related to circles – 
• Area of a sector
• Length of an arc
• Surface areas and volume – 
• TSA/LSA of cube, cuboid
• TSA/CSA of cylinder, cone
• TSA/CSA of sphere, hemisphere
• Statistics – 
• Finding mean – Direct method, Assumed mean method, Step deviation method
• Finding median
• Finding mode 
• Empirical formula relationship among mean, mode and median
• Probability – 
• Probability of the given event
• Sum of the probability of the given event and the probability of its complementary event

A detailed list of chapters and theorems:

• Triangles –
• Basic proportionality theorem
• Circles –
• Tangent – radius theorem
• Lengths of the tangents drawn from an external point
• Trigonometry –
• cos² A + sin² A = 1

CBSE Class 10 - Science - Life processes - Heterotrophic Nutrition - Topic-wise Notes

Overview of Heterotrophic Nutrition

Heterotrophic nutrition varies among organisms based on their specific adaptations to the environment. The method of obtaining nutrition is primarily determined by:

• Type of food material
• Availability of food
• Method of acquisition (how the organism accesses food)

Factors Influencing Nutritive Apparatus

The digestive system or "nutritive apparatus" of an organism evolves based on the nature of its food source.

Food Source Nature	Example	Organism	Implication
Stationary	Grass	Cow	Requires specific apparatus to access/digest stationary plants.
Mobile	Deer	Lion	Requires different apparatus for hunting and consuming moving prey.

Strategies of Food Intake and Digestion

Organisms utilize different strategies to break down and absorb nutrients:

1.  External Digestion (Saprophytic Nutrition)

• Mechanism: The organism breaks down food material outside the body and then absorbs the nutrients.
• Examples: Fungi such as:
• Bread moulds
• Yeast
• Mushrooms

2. Internal Digestion (Holozoic Nutrition)

• Mechanism: The organism takes in (ingests) whole material and breaks it down inside the body.
• Dependencies: The specific type of food taken in depends on the organism's body design and functioning.

3. Parasitic Nutrition

• Mechanism: The organism derives nutrition from other plants or animals (hosts) without killing them.
• Examples:
• Plants: Cuscuta (Amar-bel)
• Insects/Arachnids: Ticks, Lice
• Worms: Leeches, Tape-worms

MCQs: Overview of Heterotrophic Nutrition

1. Heterotrophic nutrition mainly depends on

• A. Size of the organism
• B. Type, availability, and method of acquiring food
• C. Habitat only
• D. Presence of chlorophyll

2. The nutritive apparatus of an organism is influenced by

• A. Climate
• B. Nature of the food source
• C. Age of the organism
• D. Population size

3. A lion has a different digestive and feeding apparatus than a cow because

• A. Lion lives in forests
• B. Cow is domesticated
• C. Lion feeds on mobile prey while cow feeds on stationary plants
• D. Cow eats more food

4. Nutrition in mushroom is characterised by

• A. Internal digestion
• B. External digestion followed by absorption
• C. Feeding on living host
• D. Ingestion of whole food

5. Nutrition in amoeba involves

• A. Absorption of dissolved food
• B. External digestion
• C. Ingestion and internal digestion of food
• D. Feeding without killing host

6. Which of the following pairs is correctly matched?

• A. Saprophytic nutrition — Lion
• B. Parasitic nutrition — Mushroom
• C. Parasitic nutrition — Cuscuta
• D. Holozoic nutrition — Yeast

CBSE Class 10 - Science - Differentiate between Pollination and Fertilisation

 

Frequently asked questions:

Differentiate between Pollination and Fertilisation

Differentiate between Pollination and Fertilisation
Pollination	Fertilisation
It is the transfer of pollen grains from anther to stigma.	It is the fusion of male and female gametes.
It's a physical process.	It's a biological process.
It occurs on the stigma of a flower.	It occurs inside the ovule.
It takes place before fertilisation.	It takes place after pollination.
No zygote is formed.	Zygote is formed after the fertilisation.
It may need external agents like wind, water, insects, animals, etc.	No external agents required.

CBSE Class 10 - Science - Electricity - Important Definitions

 Important definitions:

• One ampere: One ampere is the current constituted by the flow of one coulomb of charge per second.
• One volt: One volt is the potential difference between two points in a current carrying conductor when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.
• One ohm: If the potential difference across the two ends of a conductor is 1 V and the current through it is 1 A, then the resistance R, of the conductor is 1 Ω.
• One watt: One watt is the power consumed by a device that carries 1 A of current when operated at a potential difference of 1 V.
• One unit of electric energy: One unit of electric energy is the energy consumed when 1 kilowatt of power is used for 1 hour.

CBSE Class 10 - Science - Differentiate between Saturated Hydrocarbons and Unsaturated Hydrocarbons

Frequently asked questions:

Differentiate between Saturated Hydrocarbons and Unsaturated Hydrocarbons 

CBSE Class 10 - Electricity - Important formulae

 
 Important information/formulae

Sr. No.	Description	Formula	More information
1	Relationship between current and charge	𝑰=	Where, I – current Q – charge t – time
2	Relationship between potential difference, work done and charge	𝑽=	Where, V – potential difference W – work done Q – charge
3	Ohm’s law	V = IR	Where, V – potential difference I – current R – Resistance
4	Resistance	𝑹 =	Where, R – resistance of a wire l – length of the wire A – cross-section area of the wire ρ – resistivity of the conducting material of the wire
5	Electric power	P = VI Or P = I2R Or P =	Where, P – electric power V – potential difference I – current R – resistance of the conductor
6	Joule’s law of heating	H = I2Rt	Where, H – heat energy I – current R – resistance t – time
7	System of 3 resistors connected in series	Rs = R1 + R2 + R3	Where, Rs - Effective resistance of the series combination of three resistors R1, R2 and R3
8	System of 3 resistors connected in parallel	=  +  +	Where, Rp – Effective resistance of the parallel combination of the three resistors R1, R2 and R3

CBSE Class 10 - Electricity - Important Information

Important information/formulae 

Sr. No.	Physical quantity	SI Unit
1	Electric charge	C (coulomb)
2	Electric current	A (ampere)
3	Potential difference	V (volt)
4	Resistance	Ω (ohm)
5	Heat energy	J (joule)
6	Electric power	W (watt)

Sr. No.	SI unit
1	1 ampere	1 A = 1 C/1 s
2	1 volt	1 V = 1 J/1 C
3	1 ohm	1 Ω = 1 V/1 A
4	1 watt	1 W = 1 V x 1 A

Sr. No.	Quantity	Value
1	Charge on 1 electron	1.6 x 10-19 C
2	1 mA	1 x 10-3 A
3	1 μA	1 x 10-6 A
4	1 unit electrical energy	1 kWh 3.6 x 106 J
5	1 kW	1 x 103 W

CBSE Class 10 - Science - Human eye and the colourful World - Numericals

 

CBSE Class 10 – Science

Human Eye & The Colourful World

 1.     If the concave lens of focal length (f = 1.5m) used to restore the proper vision, then what is the power of lens? (-0.67 D)

 2.     A person having a myopic eye used the concave lens of focal length 50 cm. What is the power of the lens? (-2.0 D)

 3.     The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem? (-1.25 D)

 4.     A short-sighted person cannot see clearly beyond 2 m. Calculate the power of lens required to correct his vision. (-0.5 D)

5.     A myopic person uses specs of power – 0.5 D. What is the distance of far point of his eye? (200 cm in front of the eyes)

6.     The far point of a myopic person is 150 cm in front the eye. Calculate the focal length and power of a lens required to enable him to see distant objects clearly. (-150 cm, -0.67 D) 

7.     A person wears eye glass of focal length 70 cm what is the far point of the person? (70 cm in front of the eyes)

8.     If your eye glasses have focal length 60 cm what is your near point? (42.9 cm in front  of the eyes)

9.     A person suffering from far – sightedness wears a spectacle having a convex lens of focal length 50 cm. What is the distance of the near point of his eye? (50 cm in front of the eyes)

10.  The near point of a hypermetropic eye is at 75 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye? (+2.67 D)

11.  A person wants to read a book placed at 20 cm, whereas near point of his eye is 30 cm. calculate the power of the lens required. (+1.67 D)

12.  A certain person has minimum distance of distinct vision of 150 cm. He wishes to read at a distance of 25 cm. What focal length glass should he use? What is the nature of eye defect? (+30 cm, convex lens)

13.  The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that near point of the normal eye is 25 cm. (+3.0 D)

14.  A person needs a lens of power +3 D for correcting his near vision and -3 D for correcting his distant vision. Calculate the focal lengths of the lenses required to correct these defects. (+33.33 cm, -33.33 cm)

15.  A 52-year-old near-sighted person wears eye glass of power of –5.5D for distance viewing. His doctor prescribes a correction of +1.5D in the near-vision section of his bifocals this measured relative to the main parts of the lens:

a.      What is the focal length of his distance viewing part of the lens? (-18.18 cm)

b.     What is the focal length of the near vision section of the lens? (+66.67 cm)

16.  A person is able to see objects clearly only when these are lying at distance between 50 cm and 300 cm from his eye.

a.      What kind of defect of vision he is suffering from? (Myopia and Hypermetropia)

b.     What kind of lenses will be required to increase his range of vision from 25 cm to infinity? (Concave lens and Convex lens)