- #1
iitjee10
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I was trying to calculate the self inductance (per unit length) of the following system using two methods:
System : A long current carrying wire of radius R carrying uniform current density and the same current returning along the surface. (Assuming that the surface is insulated by a very thin sheet).
Method 1 : I calculated B inside and found out flux. Then I used [tex]\Phi = LI[/tex]
The answer came out to be [tex]\frac{\mu_{o}}{4\pi}[/tex]
Method 2 : I calculated the energy associated with the magnetic field and equated it to [tex]\frac{1}{2}LI^{2}[/tex]. The answer came out to be [tex]\frac{\mu_{o}}{8\pi}[/tex]
Which one is correct and where is the mistake in the wrong one ?
System : A long current carrying wire of radius R carrying uniform current density and the same current returning along the surface. (Assuming that the surface is insulated by a very thin sheet).
Method 1 : I calculated B inside and found out flux. Then I used [tex]\Phi = LI[/tex]
The answer came out to be [tex]\frac{\mu_{o}}{4\pi}[/tex]
Method 2 : I calculated the energy associated with the magnetic field and equated it to [tex]\frac{1}{2}LI^{2}[/tex]. The answer came out to be [tex]\frac{\mu_{o}}{8\pi}[/tex]
Which one is correct and where is the mistake in the wrong one ?