1.

Show that the charges oscillate with a frequency given byomega = (1)/( sqrt(LC))when a charged capacitor of capacitance C is connected to an inductor of inductance L.

Answer»

Solution :
Consider a capacitor of capacitance C. Let it be CHARGED `q_0` and connected to an ideal inductor of inductance L as shown in fig.
The capacitor begins to discharge. As it does so an emf is induced in the inductor. At any instant p.d. across the capacitor = p.d. across the inductor.
`(q)/(C ) =-L(dI)/( dt)`
`(q)/(C ) +l (DL)/(dt)=0`
Where, q and I are the charge and current at any instant
But ` I=(dI)/(dt)to (2)`
`therefore(q)/(C )+L ((d)/(d t)) ((dq)/( dt)) =0`
` ((d^2 q)/(dt^2))+(q)/(LC) =0TO (3)`
The above relation is in the FORM of
` (d^2x)/( dt^2)+ omega ^2x=0to (4)`
On comparing (3) and (4) we GET
`omega^2= (1)/(LC)`
` omega=(1)/(sqrt(LC))`


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