Physics Times 07.2019

(II) Equivalent inductance(when M0)

When fluxes support each other

L L L M   1 2 2

When fluxes oppose each other

L L L M   1 2 2

where M- Mutual inductance

M K L L 1 2, K- Coupling constant

14. Coupling constant(K)

K 1

Ideal coupling(Coaxial fashion)

0  K 1, M K L L 1 2

If d- decreases  K 1

No coupling,

(^) K   0 M 0
No coupling, (^) K   0 M 0
Unless it is specified always assume that M=0

14. Coupling constant(K)


15. LC Oscillations15. LC Oscillations
    A charged capacitor C is connected to an inductor L, the charge and current in the circuit start oscillating
    simple harmonically.

Energy in the capacitor is

(^22) cos^2
2 2
o
C
q q t
U
C C

 