10th class physics important questions 2026

CBSE Class 10 Physics is one of the most important and scoring subjects in your board examination. Whether you are preparing for school exams or the final CBSE Board 2026 exam, understanding the key concepts and practicing important questions is the best strategy. In this article, we have put together the most expected and frequently asked questions from all major Physics chapters — explained in simple, easy language so that every student can follow along without any difficulty.

01

Light — Reflection and Refraction

Chapter 9  ·  High Weightage  ·  5–6 marks expected

Light is one of the most important chapters for CBSE Class 10 Physics. Every year, at least one long question (3–5 marks) appears from this chapter. You must understand how mirrors and lenses work, and be able to draw clear ray diagrams.

🔑 Key Concept — Mirror Formula

The mirror formula connects the object distance (u), image distance (v), and focal length (f) of a spherical mirror. Memorize this formula and practice at least 10 numerical problems before the exam.

1/f = 1/v + 1/u
Magnification: m = –v/u = h'/h

⭐ Important Question 1 — 3 Marks

Define the principal focus of a concave mirror. An object 2 cm high is placed at a distance of 10 cm from a concave mirror of radius of curvature 30 cm. Find the position, nature, and size of the image formed.

💡 Tip: First find f from R (f = R/2 = 15 cm), then use 1/v = 1/f − 1/u. Show all steps for full marks.

⭐ Important Question 2 — 2 Marks

What is refraction of light? State the two laws of refraction of light.

💡 Tip: Write Snell's Law clearly: sin i / sin r = constant (refractive index). Always mention the normal in your answer.

🔥 Very Important — 5 Marks

Draw a ray diagram to show the formation of image by a convex lens when the object is placed between the optical centre and the focus. State the nature, position, and size of the image. Also write the lens formula and define power of a lens with its SI unit.

💡 Tip: Practice the ray diagram carefully. Power of lens = 1/f (in metres) and its SI unit is Dioptre (D).

Refraction and dispersion of light through a glass prism — a core concept in Class 10 Physics Chapter on Light. (Photo: Unsplash)

02

Electricity

Chapter 11  ·  Highest Weightage  ·  7–8 marks expected

Electricity is the most scoring chapter in Class 10 Physics. It has both theory questions and numerical problems. Ohm's Law, resistance in series and parallel, Joule's Law, and electric power are the most important topics. Every year, numericals from this chapter appear in the board exam.

🔑 Key Concept — Ohm's Law

Ohm's Law states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) across its ends, provided the temperature and other physical conditions remain constant. V = I × R, where R is resistance measured in Ohms (Ω).

V = I × R  |  P = V × I = I²R = V²/R
Series: R_total = R₁ + R₂ + R₃
Parallel: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃

🔥 Very Important — 5 Marks

Three resistors of 5Ω, 10Ω, and 15Ω are connected in parallel across a 30V battery. Calculate (i) current through each resistor, (ii) total resistance, and (iii) total current in the circuit.

💡 Tip: Use I = V/R for each branch separately, then use 1/R formula for total resistance. This type of numerical is asked almost every year.

⭐ Important Question — 3 Marks

State Joule's Law of heating. An electric iron of resistance 20Ω draws a current of 5A. Calculate the heat developed in 30 seconds.

💡 Tip: Joule's Law: H = I²Rt. Here H = 5² × 20 × 30 = 15,000 J. Write the formula first, then substitute values step by step.

⭐ Important Question — 2 Marks

What is the difference between resistance and resistivity? On what factors does the resistance of a conductor depend?

💡 Tip: Resistance depends on length (l), cross-sectional area (A), and material (ρ). Formula: R = ρl/A. Resistivity depends only on material and temperature.

03

Magnetic Effects of Electric Current

Chapter 12  ·  Medium–High Weightage  ·  4–5 marks expected

This chapter covers how electricity and magnetism are connected. You need to understand Fleming's Left-Hand Rule, Fleming's Right-Hand Rule, and how an electric motor and generator work. These topics are very commonly asked in board exams in the form of short and long answer questions.

🔑 Key Concept — Fleming's Rules (Easy Way to Remember)

Left-Hand Rule is for Motors — the thumb points in the direction of force on the conductor, the index finger in the direction of the magnetic field, and the middle finger in the direction of current. Right-Hand Rule is for Generators. Remember: Left = Motor (doing work), Right = Generator (producing electricity).

🔥 Very Important — 5 Marks

With the help of a labelled diagram, explain the working of an AC generator. State the principle on which it works and mention at least two differences between an electric motor and a generator.

💡 Tip: AC Generator works on electromagnetic induction (Faraday's Law). Draw a neat diagram with armature coil, magnets, slip rings, and brushes. This 5-mark question is extremely common in board exams.

⭐ Important Question — 3 Marks

What is electromagnetic induction? State Faraday's laws of electromagnetic induction. In what way is an electric generator different from an electric motor?

💡 Tip: Motor converts electrical energy → mechanical energy. Generator converts mechanical energy → electrical energy. Write this difference clearly for full marks.

Understanding electric circuits is at the heart of Class 10 Physics. Electricity and Magnetic Effects chapters together carry the highest weightage. (Photo: Unsplash)

04

Sources of Energy

Chapter 13  ·  Low–Medium Weightage  ·  2–3 marks expected

⭐ Important Question — 2 Marks

What are the advantages of using solar energy? Mention two limitations of solar energy as a source of electricity.

💡 Tip: Advantage — free, renewable, non-polluting. Limitation — depends on sunlight, high initial cost, not effective at night or on cloudy days.

⭐ Important Question — 3 Marks

What is a good fuel? Explain why we look for alternative sources of energy. Compare the advantages and disadvantages of using biogas and fossil fuels.

💡 Tip: A good fuel has high calorific value, burns without smoke, is easily available, and is affordable. Biogas is renewable and cleaner; fossil fuels are non-renewable and cause pollution.

📝 Final Exam Tips for Class 10 Physics 2026

Scoring well in the Class 10 Physics board exam is very much possible if you follow a smart strategy. Here are the most important tips to keep in mind during your preparation.

Practice ray diagrams daily. At least one ray diagram question appears every year in the Light chapter. Your diagram must be neat, properly labelled with arrows on rays, and drawn using a ruler. Students who draw clean diagrams get full marks even if their numerical answer has a minor error.

Memorize all formulas with their units. For Electricity, you must know V = IR, P = VI, H = I²Rt, R = ρl/A, and the series/parallel resistance formulas. For Light, know the mirror formula, lens formula, and magnification formulas. Write them on a sheet and revise every morning.

Attempt all questions. CBSE Physics paper has internal choice in most long questions. Read both options carefully before answering and choose the one where you are more confident. For numericals, always write the given data, formula used, substitution, and final answer with units — even a partially correct solution can earn partial marks.

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