Top Important Questions for Class 10 (P.C.B.)
If you are targeting high scores in board exams, these Class 10 Science Important Questions are designed exactly at the board level with detailed explanations, numericals, reasoning, and concept clarity. Unlike basic question lists, this article focuses on how to write answers in exams, which is the key to scoring 90%+ marks. These Class 10 Science Important Questions are strictly based on NCERT and recent exam patterns, ensuring you are fully prepared.
Why These Class 10 Science Important Questions Are Crucial
In Class 10, examiners do not just check answers—they evaluate:
- Concept clarity
- Stepwise explanation
- Diagram understanding
- Application of formulas
These Class 10 Science Important Questions are structured to help you master all these aspects.
Physics Important Questions (Class 10)
1. Define electric current and derive its formula
Electric current is defined as the rate of flow of electric charge through a conductor. When charges move through a circuit, current is produced.
Mathematically,
I = Q / t
where Q is charge and t is time.
This formula helps calculate current in circuits. In exams, always mention the unit Ampere (A).
2. A current of 3 A flows through a conductor for 4 minutes. Calculate charge
First convert time into seconds:
t = 4 × 60 = 240 s
Now apply formula:
Q = I × t = 3 × 240 = 720 C
This type of numerical is very common in board exams.
3. State Ohm’s Law and explain with formula
Ohm’s Law states that at constant temperature, current flowing through a conductor is directly proportional to voltage.
V = IR
This relation is used to calculate unknown quantities in circuits. Always mention the condition “constant temperature” for full marks.
4. Define resistance and explain factors affecting it
Resistance is the opposition offered by a conductor to the flow of current.
It depends on:
- Length (more length → more resistance)
- Area (more area → less resistance)
- Material (different materials have different resistivities)
- Temperature
5. Explain resistors in series and parallel
In series: same current flows, total resistance increases
In parallel: same voltage across each resistor, total resistance decreases
Parallel combination is used in household wiring because appliances work independently.
6. Define electric power and derive formula
Electric power is the rate at which electrical energy is consumed.
P = VI
Also, P = I²R and P = V²/R
Unit: Watt (W)
These formulas are very important for numericals.
7. What is heating effect of current?
When current flows through a conductor, electrical energy converts into heat energy.
Used in heaters, irons, and bulbs.
8. Explain magnetic field around a current-carrying conductor
When current flows through a wire, it produces a magnetic field around it in the form of concentric circles.
Direction is given by the right-hand thumb rule.
9. State Fleming’s Left Hand Rule
It helps determine the direction of force on a current-carrying conductor in a magnetic field.
Thumb → force
Forefinger → magnetic field
Middle finger → current
10. What is electric motor? Explain working
An electric motor converts electrical energy into mechanical energy using magnetic effects of current.
Chemistry Important Questions (Class 10)
11. What is a chemical reaction? Explain types with examples
A chemical reaction is a process where new substances are formed.
Types include combination, decomposition, displacement, and double displacement reactions.
12. Balance the equation: Fe + H₂O → Fe₃O₄ + H₂
Balanced equation:
3Fe + 4H₂O → Fe₃O₄ + 4H₂
Balancing is essential for scoring full marks.
13. Define oxidation and reduction with examples
Oxidation = loss of electrons or addition of oxygen
Reduction = gain of electrons or removal of oxygen
Both occur together in redox reactions.
14. What is corrosion? How can it be prevented?
Corrosion is the slow destruction of metals due to reaction with environment.
Prevention methods include painting, oiling, galvanization, and alloying.
15. What are acids, bases, and salts?
Acids produce H⁺ ions, bases produce OH⁻ ions, and salts are formed from neutralization reactions.
16. Explain pH scale and its importance
pH scale ranges from 0 to 14.
Below 7 → acidic
Above 7 → basic
Used to measure strength of acids and bases.
17. What is electrolysis?
Electrolysis is the process of breaking compounds using electric current.
Used in extraction of metals.
18. What is reactivity series?
Arrangement of metals based on their reactivity.
Helps predict displacement reactions.
19. What are hydrocarbons?
Compounds containing only carbon and hydrogen.
Examples include methane and ethane.
20. What is homologous series?
A group of compounds with similar properties and same functional group.
Biology Important Questions (Class 10)
21. What are life processes?
Life processes include nutrition, respiration, transportation, and excretion, which are essential for survival.
22. Explain human digestive system
Food is broken down in mouth, stomach, and intestines into simpler substances which are absorbed into blood.
23. What is respiration? Explain types
Respiration is the process of releasing energy from food.
Aerobic respiration uses oxygen, anaerobic does not.
24. What is transportation in humans?
Blood transports oxygen, nutrients, hormones, and waste products throughout the body.
25. What is excretion? Explain in humans
Excretion removes metabolic waste through kidneys, lungs, and skin.
26. What is control and coordination?
The nervous system and hormones regulate body activities and responses.
27. What is reproduction? Explain types
Reproduction ensures continuity of species.
Types: sexual and asexual reproduction.
28. What is heredity?
Transmission of traits from parents to offspring through genes.
29. What is evolution?
Gradual development of organisms over time due to natural selection.
30. What is ecosystem? Explain components
An ecosystem includes biotic (living) and abiotic (non-living) components interacting together.
Why These Class 10 Science Important Questions Are High-Value
These Class 10 Science Important Questions:
- Match board exam pattern
- Include numericals + theory + reasoning
- Provide step-by-step explanations
- Focus on high-weightage chapters
Final Revision Strategy
Revise these Class 10 Science Important Questions at least 2–3 times. Focus on diagrams, formulas, and structured answers. Practice writing full-length answers for maximum marks.
FAQ – Class 10 Science Important Questions
Q1. Are these enough for boards?
Yes, these cover high-weightage topics.
Q2. Are numericals important?
Yes, especially in Physics.
Q3. Are these NCERT-based?
Yes, fully aligned.
Q4. How to score 90%+?
Concept clarity + revision.
Q5. Should I revise multiple times?
Yes, at least 2–3 revisions.