Class 12 Physics Chapter 1 Electric Charges and Fields covers Coulomb's law, electric fields, dipoles, and Gauss's law. The chapter carries 6 marks in CBSE boards and appears regularly in JEE Main and NEET. Download the formula sheet PDF from this page for quick, single-page revision.
- CBSE weightage: 6 marks - Coulomb's law, Gauss's law derivation, dipole questions
- JEE Main: 4-5% of paper; axial and equatorial dipole fields, flux through surfaces
- NEET: 1-2 MCQs per year; charge quantisation, field-line properties, basic Coulomb
- 10 core formulas on one A4 page, verified against 2026-27 NCERT
Class 12 Physics Chapter 1 Formula Sheet: Complete Reference
The 10 formulas below cover every numerical in Electric Charges and Fields. Each row gives the concept, the formula, and the SI unit. Students can use this table alongside the PDF for quick lookup during practice.
| Concept | Formula | SI Unit |
|---|---|---|
| Coulomb's law | F = k q_1 q_2 / r squared | newton |
| Electric field (point charge) | E = k Q / r squared | N/C |
| Dipole moment | p = q (2a) | C m |
| Dipole field (axial) | E_axial = 2 k p / r cubed | N/C |
| Dipole field (equatorial) | E_eq = k p / r cubed | N/C |
| Torque on dipole | tau = p cross E | N m |
| Electric flux | phi = integral E . dA | V m |
| Gauss's law | closed integral E . dA = Q_enc / epsilon_0 | n/a |
| Field of infinite wire | E = lambda / (2 pi epsilon_0 r) | N/C |
| Field of plane sheet | E = sigma / (2 epsilon_0) | N/C |
Use this table for night-before revision. Cover the formula column and check that you can write each formula from memory before the boards.
Coulomb's Law - force between two point charges.
Electric Charges and Fields Video Lecture
Source: PW Vidyapeeth on YouTube
Topic-by-Topic Breakdown for Electric Charges and Fields
The chapter splits into five sub-topics. Each links to a specific formula or set of formulas in the sheet above.
- Electric charge and its properties: 1-mark MCQ on quantisation q = ne, conservation
- Coulomb's law and superposition: 3-mark numerical, vector form F = kq1q2 r_hat / r squared
- Electric field, field lines, dipole: 3 to 5-mark derivation; dipole field on axial and equatorial lines
- Electric flux and Gauss's law: 5-mark derivation; infinite line, plane sheet, spherical shell
- Continuous charge distributions: 3-mark conceptual on lambda, sigma, rho densities
Chapter 1 Weightage in CBSE, JEE Main, and NEET
Chapter 1 carries 6 marks in CBSE boards on average. The table below maps how it compares with other Class 12 Physics chapters.
| Chapter | Topic | Avg CBSE Marks |
|---|---|---|
| Ch 1 | Electric Charges and Fields | 6 marks |
| Ch 2 | Electrostatic Potential and Capacitance | 7 marks |
| Ch 3 | Current Electricity | 7 marks |
| Ch 4 | Moving Charges and Magnetism | 6 marks |
| Ch 5 | Magnetism and Matter | 3 marks |
| Ch 6 | Electromagnetic Induction | 5 marks |
| Ch 7 | Alternating Current | 6 marks |
| Ch 8 | Electromagnetic Waves | 2 marks |
| Ch 9 | Ray Optics and Optical Instruments | 7 marks |
| Ch 10 | Wave Optics | 5 marks |
| Ch 11 | Dual Nature of Radiation and Matter | 4 marks |
| Ch 12 | Atoms | 3 marks |
| Ch 13 | Nuclei | 3 marks |
| Ch 14 | Semiconductor Electronics | 6 marks |
Previous year question patterns for Chapter 1 across major exams:
| Year | CBSE Board | JEE Main | NEET |
|---|---|---|---|
| 2026 | Gauss's law derivation (3 marks) | Dipole field on axial line (4 marks) | Coulomb's law and Gauss's law (electric field, dipole) |
| 2025 | Coulomb force on three point charges (5 marks) | Electric flux through closed surface (4 marks) | Field due to dipole (4 marks) |
| 2024 | Electric field of an infinite sheet (3 marks) | Force between two charges in medium | Quantisation of charge MCQ |
| 2023 | Dipole in uniform external field (5 marks) | Linear charge density on a wire | Coulomb's law SI unit MCQ |
| 2022 | Gauss's law applied to a charged shell (3 marks) | Superposition of three charges | Electric field lines property |
| 2021 | - | Force on a dipole in non-uniform field | Field due to point charge |
Electric field - definition, units, and source.
Common Mistakes in Electric Charges and Fields
Mistake 1: Substituting values before simplifying the formula symbolically. Always rearrange to isolate the unknown first.
Mistake 2: Forgetting unit conversion. Use SI units everywhere unless the question specifies otherwise.
Mistake 3: Using approximate constants (k = 9 x 10^9 vs the exact 8.99 x 10^9). For 5-mark numericals, use the value given in the question.
Mistake 4: Confusing axial vs equatorial dipole formulas. The formula sheet table above separates them clearly.
Each mistake costs 1 to 2 marks in boards.
Student Feedback
In a Collegedunia poll of 13,150 Class 12 Physics students before the 2026 boards, 74% rated the formula sheet as their most-used revision resource, ahead of full chapter notes and solved-example PDFs.
- 74% of students placed the formula sheet at the top of their revision list.
- 58% reviewed it daily in the last 7 days before boards.
- 4 out of 5 students keep a printed copy in their notebook.
- 67% used the formula sheet alongside Chapter Notes for night-before revision.
Source: 2025-26 Class 12 Physics student poll, 13,150 students from CBSE schools across 16 states.
Other Resources for Class 12 Electric Charges and Fields
| Resource Type | Link |
|---|---|
| Formula Sheet | Electric Charges and Fields Formula Sheet |
| Notes | Electric Charges and Fields Notes |
| NCERT Solutions | Electric Charges and Fields NCERT Solutions |
| NCERT Book PDF | Electric Charges and Fields NCERT Book PDF |
| Exemplar Book PDF | Electric Charges and Fields NCERT Exemplar Book PDF |
| Exemplar Solutions | Electric Charges and Fields NCERT Exemplar Solutions |
| Handwritten Notes | Electric Charges and Fields Handwritten Notes |
NCERT Formula Sheets for Class 12 Physics: All Chapters
| Chapter | Resource |
|---|---|
| Chapter 1 | Electric Charges and Fields Formula Sheet |
| Chapter 2 | Electrostatic Potential and Capacitance Formula Sheet |
| Chapter 3 | Current Electricity Formula Sheet |
| Chapter 4 | Moving Charges and Magnetism Formula Sheet |
| Chapter 5 | Magnetism and Matter Formula Sheet |
| Chapter 6 | Electromagnetic Induction Formula Sheet |
| Chapter 7 | Alternating Current Formula Sheet |
| Chapter 8 | Electromagnetic Waves Formula Sheet |
| Chapter 9 | Ray Optics and Optical Instruments Formula Sheet |
| Chapter 10 | Wave Optics Formula Sheet |
| Chapter 11 | Dual Nature of Radiation and Matter Formula Sheet |
| Chapter 12 | Atoms Formula Sheet |
| Chapter 13 | Nuclei Formula Sheet |
| Chapter 14 | Semiconductor Electronics Formula Sheet |
Class 12 Physics Chapter 1 Electric Charges and Fields Formula Sheet FAQs
Ques. How many formulas are in the Class 12 Chapter 1 physics formula sheet?
Ans. 10 formulas cover every numerical the chapter generates. The Quick-Reference Table above lists them with units. The PDF carries the same list on a single A4 page for night-before revision.
Ques. What is the weightage of Class 12 Physics Chapter 1?
Ans. Chapter 1 carries 6 marks in CBSE Class 12 Physics, 4 to 5% in JEE Main, and 1 to 2 questions per year in NEET. The formula sheet covers all formulas needed for every exam track.
Ques. Where can I download the Class 12 Chapter 1 physics formula sheet PDF?
Ans. The PDF is available directly on this page via the flipbook above. It includes all 10 formulas plus JEE and NEET extensions on a single A4 page.
Ques. Are the JEE Main extensions covered in this formula sheet?
Ans. Yes. The formula sheet includes 2-3 extensions that JEE Main and JEE Advanced test but CBSE boards rarely ask. These are flagged with a distinct marker in the PDF.
Ques. What is the most-asked formula in Electric Charges and Fields?
Ans. Coulomb's law is the foundational formula and appears in most Chapter 1 numericals. The full list of high-frequency formulas is in the Quick-Reference Table above.
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