Moving Charges And Magnetism Flashcards
(22 cards)
Radius curvature of a particle in magnetic field
- R = mv/qB
- R = √(2mK) / qB
K: kinetic energy
m: mass
Biot savarts law
dB = μₒ/4π idℓsinθ/r²
Magnetic field due to straight wire
μₒi / 2πa
Magnetic field at centre of circular loop
μₒi/ 2a
Magnetic field at centre of semicircular loop
½ (μₒi / 2a)
Magnetic field at any point on the axis of circular loop
μₒiR² / 2 (R² + x²) ^3/2
R: radius of loop
x: distance from centre
Ampere circuital law
∫B.dℓ = μₒi
Magnetic field due to solenoid
- Inside: μₒni
- outside: μₒni/2
Magnetic field due cylindrical wire with uniform current distribution
- inside:
μₒia / 2πr² - outside:
μₒi / 2πa
a: distance from centre
r: radius
Force experienced by current carrying wire in uniform magnetic field
- F = BIℓ sinθ
- F = I (ℓ × B)
Magnetic dipole moment
μ = NIA
A: area
N: no: of turns
I: current
Force of moving charge in magnetic field
- F = qVB sinθ
- F = q (V × B)
Magnetic force between two parallel current carrying conductors
F = μₒ/4π 2I₁I₂ ℓ/ r
ℓ: smaller length
r: distance b/w wires
Finding neutral point for current carrying wire
X = I₂r / (I₁-I₂)
- I₂ < I₁
- x: distance from smaller current
- r: distance between wires
- current is flowing in opp direction in the wires
Current in parallel wires
- same direction: attractive force
- opp direction: repulsive force
Torque on current carrying loop
τ = M × B
M: magnetic dipole moment
Restoring torque in galvanometer at eqm position
Restoring torque = deflecting torque
kθ = BINA
A: area of coil
k: restoring torque
Current through galvanometer
I = Gθ
Magnetic field at centre for any arc
μₒ/4πa iθ
a: radius of arc
θ: angle in radians
Current sensitivity of moving coil galvanometer
Iₛ = θ/ I = NBA/k
Voltage sensitivity of moving coil galvanometer
Vₛ = Iₛ/R = NBA/kR
Magnetic moment energy
E = μB
μ: magnetic moment
B: magnetic field
