A 100 $\Omega$ resistance and a capacitor of 100 $\Omega$ reactance are connected in series across a 220 V source. When the capacitor is 50% charged, the peak value of the displacement current is

(1) 2.2 A             

(2) 11A

(3) 4.4A               

(4) 11$\sqrt{2}$A

A small-signal voltage V(t)=V_o sinωt is applied across an ideal capacitor C 
(1) over a full cycle, the capacitor C does not consume any energy from the voltage source

(2) current I(t) is in phase with voltage V(t)

(3) current I(t) leads voltage V(t) by 180°

(4) current I(t) lags voltage V(t) by 90°

Which of the following combinations should be selected for better tuning of an \(LCR\) circuit used for communication?
1. \(R=20~\Omega ,~L=1.5~H,~C=35~\mu F\)
2. \(R=25~\Omega ,~L=2.5~H,~C=45~\mu F\)
3. \(R=15~\Omega ,~L=3.5~H,~C=30~\mu F\)
4. \(R=25~\Omega ,~L=1.5~H,~C=45~\mu F\)