In an `L-C` circuit, `L = 0.75 H` and `C =18 muF`, (a) At the instant when the current in the inductor is changing at a rate of `3.40 Ns`, what is the charge on the capacitor? (b) When the charge on the capacitor is `4.2 xx 10^-4` C, what is the induced emf in the inductor?

Explanation

a. `V_L=V_C`
`L(di)/(dt)=q/C`
`q=(LC)=(di)/(dt)`
`=0.75xx18xx10^Y-6)(3.4)`
`=45.9xx10^-6C`
`=45.9muC`
b. `V_(L) = V_(C) = (q)/(C)`
`= (4.2 xx 10^(-4))/(18 xx 10^(-6))`
`= 23.3 V`