Magnetic Field of Circular Current

Field at center of ring (z = 0): Bz = µ0I. 2R. • Magnetic moment: µ = IπR. 2. • Field at large distance (z ≫ R) : Bz ≃. µ0. 2π. µ z3. 28/3/2011. [tsl214 – 6/14]
75KB taille 1 téléchargements 441 vues
Magnetic Field of Circular Current • Law of Biot and Savart: dB = • dBz = dB sin θ = dB √

µ0 Idℓ 4π z 2 + R2

R

z 2 + R2 Rdℓ µ0 I ⇒ dBz = 4π (z 2 + R2 )3/2 Z 2πR R µ0 I dℓ • Bz = 4π (z 2 + R2 )3/2 0 R2 µ0 I ⇒ Bz = 2 (z 2 + R2 )3/2 • Field at center of ring (z = 0): Bz =

µ0 I 2R

• Magnetic moment: µ = IπR2 • Field at large distance (z ≫ R) : Bz ≃

µ0 µ 2π z 3

28/3/2011

[tsl214 – 6/14]