Magnetism and Magnetic Effects of Electric Current Important Questions & Preparation Tips
Magnetism and Magnetic Effects of Current covers magnetic fields, magnetic forces, Biot-Savart’s law, Ampere’s circuital law, cyclotron, torque on current loops, and the moving coil galvanometer. This page includes important 2, 3, and 5 mark questions, numericals, derivations, preparation tips for the board exam.
Harmanpreet Kaur28 Sept, 2026
Mastering the 12th Physics Magnetism and Magnetic Effects of Electric Current important questions is vital for high board exam scores. This chapter carries significant weight in higher secondary physics. Questions range from direct definitions to derivations of magnetic fields around conductors.
Students build a solid foundation in electromagnetic theory through these solutions. You will learn how electric currents produce magnetic fields, and practising these targeted questions improves your analytical skills and speed in the final exam. Follow the latest Tamil Nadu HSC 12th 2027 notification for board updates.
Magnetism and Magnetic Effects of Electric Current Overview
The table below gives a quick snapshot of Chapter 3 and the resources on this page.
| Particulars | Details |
| Board | Directorate of Government Examinations (DGE), Tamil Nadu |
| Class | 12th (HSC / +2) |
| Subject | Physics |
| Chapter | Chapter 3: Magnetism and Magnetic Effects of Electric Current |
| Important 2 Mark Questions | 9 |
| Important 3 Mark Questions | 3 |
| Important 5 Mark Questions | 9 |
| Theory Marks (Physics) | 70 |
| Exam Duration | 3 hours |
Important Questions for Tamil Nadu 12th Physics Magnetism and Magnetic Effects of Electric Current
Solving structured questions helps you reinforce key laws and derivations quickly. Review the essential questions below to test your conceptual clarity. The table shows how the questions are grouped so you can plan your revision.
| Question Type | Marks | Number of Questions | What to Expect |
| Very short answer | 2 | 9 | Definitions, laws, hysteresis, and the ammeter connection |
| Short answer | 3 | 3 | Dia, para and ferromagnetism, and the velocity selector |
| Long answer | 5 | 9 | Biot-Savart and Ampere's law derivations, cyclotron, forces, and galvanometer |
12th Physics Magnetism Important 2 Mark Questions
These questions test your grasp of basic definitions and laws. Write the statement, the formula, and the SI unit in each answer to secure full marks.
| S.No. | Important 2 Mark Question |
| 1 | Define magnetic flux. |
| 2 | State Coulomb's inverse law. |
| 3 | What is magnetic susceptibility? |
| 4 | State Biot-Savart's law. |
| 5 | State Ampere's circuital law. |
| 6 | What is meant by hysteresis? |
| 7 | Define ampere. |
| 8 | State Fleming's left hand rule. |
| 9 | Is an ammeter connected in series or parallel in a circuit? Why? |
12th Physics Magnetism Important 3 Mark Questions
The 3 mark questions ask for comparisons, properties and short explanations. Present your answer in clear points, and use a table for comparison questions.
| S.No. | Important 3 Mark Question |
| 1 | Compare dia, para and ferro-magnetism. |
| 2 | Explain the concept of velocity selector. |
| 3 | Give the properties of dia / para / ferromagnetic materials. |
12th Physics Magnetism Important 5 Mark Questions
Five mark questions are mostly long derivations. Draw a neat labelled diagram, define every symbol, show each step, and write the final formula clearly.
| S.No. | Important 5 Mark Question |
| 1 | Deduce the relation for the magnetic field at a point due to an infinitely long straight conductor carrying current using Biot-Savart law. |
| 2 | Obtain a relation for the magnetic field at a point along the axis of a circular coil carrying current using Biot-Savart law. |
| 3 | Find the magnetic field due to a long straight conductor using Ampere's circuital law. |
| 4 | Discuss the working of cyclotron in detail. |
| 5 | Calculate the magnetic field inside and outside of the long solenoid using Ampere's circuital law. |
| 6 | Derive the expression for the force between two parallel, current-carrying conductors. |
| 7 | Compare the properties of soft and hard ferromagnetic materials. |
| 8 | Derive the expression for the force on a current-carrying conductor in a magnetic field. |
| 9 | Explain the principle and working of a moving coil galvanometer. |
12th Physics Magnetism Important Numerical Problems
Numericals in this chapter are formula-based and quick to score once you practise. The table gives sample problems with answers so you can check your working. Always double-check SI units and vector directions.
| S.No. | Numerical Problem | Answer |
| 1 | A proton (q = 1.6 × 10⁻¹⁹ C) moves at 2 × 10⁶ m/s perpendicular to a magnetic field of 0.5 T. Find the force on it. | 1.6 × 10⁻¹³ N |
| 2 | Find the magnetic field at 5 cm from a long straight wire carrying a current of 10 A. | 4 × 10⁻⁵ T |
| 3 | A solenoid has 1000 turns per metre and carries a current of 2 A. Find the magnetic field inside it. | ≈ 2.5 × 10⁻³ T |
| 4 | Find the force per unit length between two long parallel wires 1 m apart, each carrying 1 A in the same direction. | 2 × 10⁻⁷ N/m (attractive) |
| 5 | A conductor of length 0.5 m carrying 4 A is placed perpendicular to a magnetic field of 0.2 T. Find the force on it. | 0.4 N |
| 6 | Find the magnetic field at the centre of a circular coil of 50 turns and radius 0.1 m carrying 2 A. | ≈ 6.28 × 10⁻⁴ T |
| 7 | A coil of 100 turns and area 0.01 m² carries 2 A in a field of 0.5 T. Find the maximum torque on it. | 1 N m |
| 8 | Find the cyclotron frequency of a proton in a magnetic field of 1 T. | ≈ 1.53 × 10⁷ Hz |
12th Physics Magnetism Important Derivations
Derivations make up most of the 5 mark questions in this chapter, so learn them step by step. The table lists each derivation or explanation with its marks and the main concept it relies on.
|
S.No. |
Derivation / Explanation |
Marks |
Key Concept Used |
|
1 |
Magnetic field due to an infinitely long straight conductor |
5 |
Biot-Savart law and integration over the conductor |
|
2 |
Magnetic field on the axis of a circular coil |
5 |
Biot-Savart law and symmetry |
|
3 |
Magnetic field due to a long straight conductor |
5 |
Ampere's circuital law with a circular loop |
|
4 |
Magnetic field inside and outside a long solenoid |
5 |
Ampere's circuital law with a rectangular loop |
|
5 |
Force between two parallel current-carrying conductors |
5 |
Force on a conductor in the field of the other |
|
6 |
Force on a current-carrying conductor in a magnetic field |
5 |
Lorentz force on moving charges |
|
7 |
Working of a cyclotron |
5 |
Circular motion in a magnetic field and a resonant electric field |
|
8 |
Principle and working of a moving coil galvanometer |
5 |
Torque on a current loop and the restoring spring torque |
|
9 |
Velocity selector |
3 |
Balance of electric and magnetic forces |
Tamil Nadu 12th Physics Chapter 3 Magnetism and Magnetic Effects of Electric Current PDF Download
You can download the 12th Physics Magnetism important questions PDF for offline practice. The file allows easy revision and quick reference during your preparation.
Download 12th Physics Magnetism Questions and Answers PDF Here
Practice with Magnetism and Magnetic Effects of Electric Current Important Questions.
How to Prepare Chapter 3 Magnetism for the 12th Physics Exam?
Strategic revision ensures better memory retention and faster problem-solving during tests. Use these steps to prepare effectively.
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Review core concepts first. Read the textbook chapter carefully. Focus on Biot-Savart's law and Ampere's circuital law before attempting the questions. Check the Tamil Nadu HSC syllabus to confirm the topics.
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Practise derivations regularly. Write the major derivations by hand, and draw neat labelled diagrams for devices like the cyclotron and the moving coil galvanometer.
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Master the short answer questions. Practise the 12th Physics Magnetism 2 mark questions daily. This strengthens your grasp of definitions, units, and magnetic properties.
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Solve standard numericals. Work through calculation-based problems step by step. Always double-check SI units and vector directions.
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Revise using question sets. Use the Tamil Nadu 12th Physics Magnetism important questions for self-assessment, and time your practice to increase your exam speed. Solve the Tamil Nadu 12th Physics model papers and previous year question papers as well.
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Know the paper format. Read the Tamil Nadu Class 12 exam pattern to plan your time across the parts.
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Practise other subjects too. Balance your revision with the Tamil Nadu 12th Botany model papers if you are studying the biology group.
Magnetism and Magnetic Effects of Electric Current FAQs
1. What is the working principle of a moving coil galvanometer?
2. State Biot-Savart's law in vector form.
3. How do diamagnetic and paramagnetic materials differ?
4. What is the primary function of a cyclotron?
5. Which 5 mark questions are important in Magnetism and Magnetic Effects of Electric Current?
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