Mnemonics: Moving Charges and Magnetism | Physics Class 12 - NEET PDF Download

1. Magnetic Force on Moving Charge

Formula:

Mnemonic: "Queen Victoria Bows"

Breakdown:

• Queen – q (charge)

• Victoria – v (velocity)

• Bows – B (magnetic field)

This mnemonic helps you recall the magnetic force formula where:

A charged particle (Queen) moving with a velocity (Victoria) in a magnetic field (Bows) experiences a magnetic force.

The direction of the force is given by the right-hand rule (thumb for velocity, fingers for magnetic field, palm gives the force direction for a positive charge).

2. Biot–Savart Law Elements

Mnemonic: "Tiny Current Makes Field"

Breakdown: 

• Tiny – (tiny element of wire)

• Current – Current $I$

• Makes – Magnetic field

• Field –

The Biot–Savart Law describes how a small segment of current-carrying conductor creates a magnetic field around it. The law is given by:

This mnemonic helps you recall the essential components involved in generating a magnetic field from a current element. "Tiny Current Makes Field" paints the picture of a small current element influencing its magnetic surroundings.

3. Ampere’s Circuital Law

Mnemonic: "I Am Beautiful"

Breakdown:

• I – Current enclosed

• Am – Ampere's Law

• Beautiful – (the mathematical expression of the law)

This mnemonic helps you recall Ampere’s Circuital Law, which connects the magnetic field along a closed loop to the electric current passing through that loop.
The word "Beautiful" represents the elegant and symmetrical equation:

4. Ampere’s Circuital Law Applications

Types: Infinite Straight Wire, Solenoid, Toroid

Mnemonic: "Incredible Super Tunnel"

Breakdown:

• Incredible – Infinite Straight Wire

• Super – Solenoid

• Tunnel – Toroid

This creative mnemonic helps you recall where Ampere’s Circuital Law is typically applied:

Infinite Straight Wire – To find the magnetic field around a long current-carrying conductor

Solenoid – To analyze the magnetic field inside a coil of wire

Toroid – For calculating the magnetic field in a donut-shaped coil.

5. Magnetic Properties of Materials

Types: Diamagnetic, Paramagnetic, Ferromagnetic

Mnemonic: "Don’t Panic, Friend!"

Breakdown:

• Don’t – Diamagnetic

• Panic – Paramagnetic

• Friend – Ferromagnetic

This mnemonic gives a sense of increasing magnetic behavior:

Diamagnetic → Very weak and repelled by magnetic fields (stay calm = don’t react)

Paramagnetic → Weakly attracted (mild response = slight panic)

Ferromagnetic → Strongly attracted and can become magnets (reliable = strong friend!)

6. Forces Between Two Parallel Currents

Types: Attraction, Repulsion, Dependence on Direction

Mnemonic: "Ants Run Downhill"

• Ants – Attraction (currents in the same direction attract each other)

• Run – Repulsion (currents in opposite directions repel each other)

• Downhill – Direction Dependence (the force depends on the direction of the currents)

Ants (Attraction): When the currents are flowing in the same direction, they attract each other, similar to how ants might gather together.

Run (Repulsion): When the currents flow in opposite directions, they repel each other, just like how things would move away if they were in opposition.

Downhill (Direction Dependence): The force between the two currents depends on the direction in which they are flowing (either attracting or repelling based on their relative direction).