In a parallel plate air capacitor, a cathode beam comprising $n = 10^6$ electrons is emitted with a velocity $v_0 = 10^8\ m/s$ into the space between the plates. The potential difference between the plate is $\phi  = 400\ V$ ,the seperation between the plates is $d = 2\ cm$ and the area of each plate is $l^2 = 100\ cm^2$ . The deflection of the electron beam, is ........... $mm$

Five indentical capacitor plates, each of area $A,$ are arranged such that adjacent plates are at distance $d$ apart. The plates are connected to a source of $emf$ $V$ as shown in fig. Then the charges $1$ and $4$ are, respectively :-

Two parallel metal plates having charges $+ Q$ and $-Q$ face each other at a certain distance between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will

In the given circuit if point $C$ is connected to the earth and a potential of $+2000\,V$ is given to the point $A$ , the potential of $B$ is.....$V$

Charge of $2Q$ and $-Q$ are placed on two plates of a parallel plate capacitor if capacitance of capacitor is $C$ find potential difference between the plates

A parallel plate capacitor with air between the plates has a capacitance of $9\, pF$. The separation between its plates is $'d'$. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant $K_1=3$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 6$ and thickness  $\frac{2d}{3}$. Capacitance of the capacitor is now....$pF$