Magnetism covers two NCERT chapters, Moving Charges and Magnetism, and Magnetism and Matter. The first is formula-heavy; the second is short and factual. This magnetism NEET PYQ analysis shows which question types NTA repeats, the results worth memorising, and the direction mistakes that cost marks.
Before diving in, make sure you have the bigger picture from our complete NEET Physics strategy. This article focuses on what past papers actually ask.
Want to test yourself first? Solve the free Moving Charges and Magnetism PYQs and Magnetism and Matter PYQs, then use this guide to fix the gaps.
Table of Contents
Why Magnetism Matters
NEET usually asks three to four questions from these two chapters together, with most coming from Moving Charges and Magnetism.
The unit follows directly from electric fields, so revise our Electrostatics PYQ patterns article first if field ideas feel shaky. It also leads into induction, covered in our Electromagnetic Induction preparation guide. With so many similar formulas, it helps to have a system so you stop forgetting Physics formulas.
Magnetism NEET PYQ Analysis: The Repeated Question Types
After sorting a decade of NEET physics PYQs from these two chapters, the questions fall into six families.
| Question family | Frequency | What it tests |
|---|---|---|
| Charge moving in a magnetic field | Most frequent | Radius, time period, path |
| Field due to current | Very frequent | Straight wire, loop, arc, solenoid |
| Force and torque on conductors | Very frequent | Parallel wires, current loop, magnetic moment |
| Moving coil galvanometer | Regular | Sensitivity, conversion to ammeter and voltmeter |
| Magnetic materials | Regular | Dia-, para- and ferromagnetism |
| Bar magnet and dipole | Regular | Magnetic moment, torque, potential energy |
For a quick warm-up before the full set, try these five repeated magnetism practice questions. The Magnetism and Matter class notes cover the second chapter in full.
Charged Particle in a Magnetic Field
- Force: F = qvB sinθ. It is always perpendicular to the velocity, so it does no work and the speed stays constant.
- If v is perpendicular to B, the path is a circle of radius r = mv/qB.
- Time period: T = 2πm/qB. It does not depend on speed or radius.
- In terms of kinetic energy K: r = √(2mK)/qB.
- If v is parallel to B, the path is a straight line. At any other angle, it is a helix.
Magnetic Field Due to Current
The Biot-Savart law gives the field of a small current element, and every result below follows from it.
| Source | Magnetic field |
|---|---|
| Long straight wire | μ₀I / 2πr |
| Centre of a circular loop | μ₀I / 2R |
| Centre of an arc of angle θ | μ₀Iθ / 4πR |
| Inside a long solenoid | μ₀nI |
Ampere’s circuital law states that the line integral of B around a closed path equals μ₀ times the current enclosed. It gives the straight wire and solenoid results quickly. Inside a long solenoid, the field is uniform; outside, it is nearly zero.
As a rule, use Ampere’s circuital law when the current distribution is symmetric, and the Biot-Savart law for loops and arcs.
Force and Torque
- Force on a current-carrying wire: F = BIL sinθ.
- Force per unit length between two parallel wires: μ₀I₁I₂ / 2πd. Currents in the same direction attract; opposite currents repel.
- Magnetic moment of a coil: M = NIA.
- Torque on a coil in a uniform field: τ = MB sinθ.
- Potential energy of a magnetic dipole: U = −MB cosθ.
Moving Coil Galvanometer
- Current sensitivity = NAB/k, where k is the torsional constant of the spring.
- To convert to an ammeter, connect a small shunt in parallel: S = I_g G / (I − I_g).
- To convert to a voltmeter, connect a high resistance in series: R = V/I_g − G.
An ideal ammeter has zero resistance, and an ideal voltmeter has infinite resistance. Moving coil galvanometer questions are almost always one of these two conversions.
Magnetism and Matter
| Property | Diamagnetic | Paramagnetic | Ferromagnetic |
|---|---|---|---|
| Susceptibility (χ) | Small, negative | Small, positive | Large, positive |
| In a non-uniform field | Moves to the weaker region | Moves to the stronger region | Strongly attracted |
| Examples | Bismuth, copper, water | Aluminium, sodium, oxygen | Iron, cobalt, nickel |
- Diamagnetism is independent of temperature.
- Paramagnetic susceptibility follows Curie’s law: χ ∝ 1/T.
- Above the Curie temperature, a ferromagnet becomes paramagnetic.
- Magnetic field lines form closed loops, so the net magnetic flux through any closed surface is zero.
Note that Earth’s magnetism is no longer in the NEET syllabus.
Worked PYQ-Pattern Questions
Q1. A proton and an alpha particle enter a uniform magnetic field with the same velocity, perpendicular to the field. What is the ratio of their radii?
Answer: 1 : 2. r ∝ m/q. For the proton it is 1/1; for the alpha particle, 4/2 = 2.
Q2. The radius of a circular coil is doubled while the current stays the same. How does the field at the centre change?
Answer: It is halved. B = μ₀I/2R, so B ∝ 1/R.
Q3. A galvanometer of resistance 50 Ω gives full-scale deflection at 10 mA. What shunt converts it into an ammeter of range 1 A?
Answer: About 0.5 Ω. S = I_g G / (I − I_g) = (0.01 × 50)/0.99 ≈ 0.505 Ω.
Q4. The kinetic energy of a charged particle moving in a circle in a magnetic field is doubled. How does the radius change?
Answer: It becomes √2 times. r = √(2mK)/qB, so r ∝ √K.
Q5. Two long parallel wires carry currents in the same direction. They will:
Answer: Attract each other.
Common Traps to Avoid
- Saying the magnetic force changes the speed of a charged particle
- Assuming the time period depends on speed
- Reversing the attract and repel rule for parallel currents
- Connecting the shunt in series or the high resistance in parallel
- Giving a diamagnet a positive susceptibility
Practise Every Magnetism PYQ
This magnetism NEET PYQ analysis gives you the formulas. The fastest way to lock them in is to solve real past questions, chapter by chapter. Both chapters are available chapter-wise, free:
👉 Solve Moving Charges and Magnetism NEET PYQs
👉 Solve Magnetism and Matter NEET PYQs
Start with moving charges, then finish the shorter second chapter in one sitting.
Conclusion
Magnetism rewards students who know a small set of results and apply the direction rules carefully. Use this magnetism NEET PYQ analysis to focus on circular motion of charges, field formulas and galvanometer conversions, then practise until each question type feels familiar.
❓ FAQ
Q: How many questions come from Magnetism in NEET? A: Usually three to four questions from Moving Charges and Magnetism and Magnetism and Matter together.
Q: What is the most important topic in Magnetism for NEET? A: The motion of a charged particle in a magnetic field is asked most often, followed by field due to current from the Biot-Savart law and galvanometer conversions.
Q: Is Earth’s magnetism in the NEET syllabus? A: No. The current syllabus covers the bar magnet, magnetic field lines and magnetic materials, but not Earth’s magnetism.
Q: Why does a magnetic field not change the speed of a charge? A: The magnetic force is always perpendicular to the velocity, so it does no work. Only the direction of motion changes.
Q: How should I revise this unit? A: Use a magnetism NEET PYQ analysis to list the repeated question types, make a one-page formula sheet, and solve past questions chapter-wise.
Q: Where can I practise Magnetism NEET PYQs for free? A: You can solve every previous year question from both chapters for free using the practice links in this article.