Magnetism formulas

Every formula JEE Advanced expects you to know for Magnetism, with the variables spelled out. Free, no sign-up. Read it before a mock, not during one.

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Formulas: 34
Subject: Physics
Exam: JEE Advanced
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Magnetism, every formula

34 formulas, typeset and free. Print it, or keep it open beside your practice.

Biot–Savart law
$d B = \frac{μ _{0}}{4 π} \frac{I d l \times r ^}{r ^{2}}$
Field of a straight wire
$B = \frac{μ _{0} I}{4 π d} (sin θ_{1} + sin θ_{2})$
Field of an infinite wire
$B = \frac{μ _{0} I}{2 π r}$
Field at centre of a loop
$B = \frac{μ _{0} N I}{2 r}$
Field on the axis of a loop
$B = \frac{μ _{0} N I R ^{2}}{2 ( R ^{2} + x ^{2} ) ^{3/2}}$
Field of a circular arc
$B = \frac{μ _{0} I α}{4 π r}$
α = arc angle
Field inside an infinite solenoid
$B = μ_{0} n I$
Field of a toroid
$B = μ_{0} n I, n = \frac{N}{2 π R}$
Ampere's circuital law
$\oint B \cdot d l = μ_{0} I$
Force on a moving charge
$F = q (v \times B)$
Lorentz force
$F = q (E + v \times B)$
Radius of circular path
$r = \frac{m v}{q B}$
Time period in a field
$T = \frac{2 π m}{q B}$
Pitch of a helix
$p = \frac{2 π m v cos θ}{q B}$
Force on a current-carrying wire
$F = I (l \times B), F = B I l sin θ$
Force between parallel wires
$\frac{F}{l} = \frac{μ _{0}}{4 π} \frac{2 I _{1} I _{2}}{r}$
Magnetic moment of a loop
$M = N I A$
Torque on a loop
$τ = M \times B, τ = N I A B sin θ$
Cyclotron frequency
$f = \frac{q B}{2 π m}$
Gyromagnetic ratio
$\frac{M}{L} = \frac{q}{2 m}$
Magnetic moment of orbiting electron
$M = \frac{e v r}{2}$
Bar magnet moment
$M = m l$
m = pole strength, l = length
Field of a magnet (axial)
$B = \frac{μ _{0}}{4 π} \frac{2 M}{r ^{3}}$
Field of a magnet (equatorial)
$B = \frac{μ _{0}}{4 π} \frac{M}{r ^{3}}$
Torque on a magnet
$τ = M B sin θ$
PE of a magnet
$U = - M B cos θ$
Work to rotate a magnet
$W = M B (cos θ_{1} - cos θ_{2})$
Earth's horizontal component
$B_{H} = B cos δ$
Angle of dip
$tan δ = \frac{B _{V}}{B _{H}}$
Magnetic susceptibility
$χ = \frac{I}{H}$
Relative permeability
$μ_{r} = 1 + χ$
Moving-coil galvanometer
$I = \frac{C}{N A B} θ$
Tangent galvanometer
$B_{c} = B_{H} tan θ$
Vibration magnetometer period
$T = 2 π \frac{I}{M B _{H}}$

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Magnetism formulas

Magnetism, every formula

Biot–Savart law

Field of a straight wire

Field of an infinite wire

Field at centre of a loop

Field on the axis of a loop

Field of a circular arc

Field inside an infinite solenoid

Field of a toroid

Ampere's circuital law

Force on a moving charge

Lorentz force

Radius of circular path

Time period in a field

Pitch of a helix

Force on a current-carrying wire

Force between parallel wires

Magnetic moment of a loop

Torque on a loop

Cyclotron frequency

Gyromagnetic ratio

Magnetic moment of orbiting electron

Bar magnet moment

Field of a magnet (axial)

Field of a magnet (equatorial)

Torque on a magnet

PE of a magnet

Work to rotate a magnet

Earth's horizontal component

Angle of dip

Magnetic susceptibility

Relative permeability

Moving-coil galvanometer

Tangent galvanometer

Vibration magnetometer period

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