$A$ capacitor of $50 \,\mu {F}$ is connected in a circuit as shown in the figure. The charge on the upper plate of the capacitor is $......\,\mu {C} .$

$A$ proton and a deuteron are initially at rest and are accelerated through the same potential difference. Which of the following is false concerning the final properties of the two particles?

Two parallel plate capacitors $C_1$ and $C_2$ each having capacitance of $10 \mu F$ are individually charged by a $100 \, V$ $D.C.$ source. Capacitor $C_1$ is kept connected to the source and a dielectric slab is inserted between its plates. Capacitor $C_2$ is disconnected from the source and then a dielectric slab is inserted in it. Afterwards,the capacitor $C_1$ is also disconnected from the source and the two capacitors are finally connected in parallel combination. The common potential of the combination will be $......... \, V$. (Assuming dielectric constant $K = 10$)

In the circuit shown in the figure,for section $AB$,$C_1 = 1\ \mu F$,$C_2 = 2\ \mu F$,$E = 10\ V$,and the potential difference $V_A - V_B = -10\ V$. Find the charge on capacitor $C_1$.

If $V_{A}-V_{B}=7 \text{ V}$,then find the stored energy in $C_1$.

$A$ body of mass $1 \,g$ and carrying a charge $10^{-8} \,C$ passes through two points $P$ and $Q$. $P$ and $Q$ are at electric potentials $600 \,V$ and $0 \,V$, respectively. The velocity of the body at $Q$ is $20 \,cm/s$. Its velocity in $m/s$ at $P$ is: