In an LC circuit shown in figure, C = 1F, L = 4H. At time t = 0, charge in the capacitor is 4C and it is decreasing at the rate of 5Cs−1. Choose the correct statement.

Given : dqdt=i=5AAt some time t,⇒qm22C=q22C+12Li2 ⇒qm22=162+1245=18⇒qmax=6Cq=Qcos⁡(ωt+δ)  at t = 0, q = 4⇒ 4=6cos⁡δ ⇒cos⁡δ=23 ⇒δ=cos−1⁡23Charge on the capacitor is maximum at t = t1 for this ωt1+δ=π⇒ t1=1ω(π−δ)=LC(π−δ)=2π−cos−1⁡23