The frequency of oscillation of a certain LC circuit is 299 kHz. At time t = 0, plate A of the capacitor has maximum positive charge. At what earliest time t > 0 will (a) plate A again have maximum positive charge, (b) the other plate of the capacitor have maximum positive charge, and (c) the inductor have maximum magnetic field?

Given an LC circuit

Frequency of oscillation

f = 299 kHz = 299,000 Hz

AT t = 0, the plate A has maximum positive charge

A. At t > 0, the plate again positive charge, the required time is

t =

t = 1 / f

t = 1 / 299,000

t = 0.00000334448 seconds

t = 3.34 * 10^-6 seconds

t = 3.34 μs

it will be maximum after integral cycle t' = 3.34•n μs

Where n = 1,2,3,4 ...

B. After every odd multiples of n, other plate will be maximum positive charge, at time equals

t" = ½ (2n-1) •t

t'' = ½ (2n-1) 3.34 μs

t" = (2n - 1) 1.67 μs

where n = 1,2,3 ...

C. After every half of t, inductor have maximum magnetic field at time

t'' = ½ * t'

t''' = ½ (2n-1) 1.67μs

t"' = (2n - 1) 0.836 μs

where n = 1,2,3 ...