Consider two point charges $+q$ and $+2 q$ fixed on the $x-y$ plane at $(-\ell / 2,0)$ and $(+\ell / 2,0)$ respectively. Another point charge $-q$ having mass $m$ is released from rest at $(0,(\sqrt{3} / 2) \ell)$ on the $x y$ plane, as shown in the figure The permittivity of free space is $\epsilon_0$. What is the acceleration of the charge $-q$ at the time of release?

Consider the circuit diagram as shown in the figure. The source has a voltage $V=V_0 \sin \omega t$. Both the resistors $A$ and $B$ have the same resistance. The capacitor and the inductor have capacitance $C$ and inductance $L$, respectively. For some frequency $\omega$, and certain initial charge in the capacitor, the current through the resistor $A$ is in phase with the source. What is the value of $\omega$ ?

A conducting wire carrying a steady current $I$ is shaped as shown in the figure below. All connected graight segments meet at right angles. What is the magnetic moment of the current loop?

Consider the shown circuit. The capacitors $C_1$ and $C_2$ have capacitances $2 \mu \mathrm{~F}$ and $8 \mu \mathrm{~F}$, respectively. The switch can connect point $X$ to either $Y$ or $Z$. Initially $X Y$ is connected until the capacitor is fully charged by the battery. Then the switch connects $X$ and $Z$, and the final charges on Cl and C 2 are $Q_1$ and $Q_2$, respectively. What is the value of the ratio $\frac{Q_2}{Q_1+Q_2}$ ?