$A$ hot filament liberates an electron with zero initial velocity. The anode potential is $1200 \,V$. The speed of the electron when it strikes the anode is

$A$ simple pendulum has a bob with mass $m$ and charge $q$. The pendulum string has negligible mass. When a uniform and horizontal electric field $\vec{E}$ is applied, the final tension in the string changes. The final tension in the string, when the pendulum attains an equilibrium position, is . . . . . . . ($g$: acceleration due to gravity)

If an $\alpha$-particle and a proton are accelerated from rest by a potential difference of $1 \text{ MV}$,then the ratio of their kinetic energy will be

$A$ simple pendulum of length $L$ is placed between the plates of a parallel plate capacitor having an electric field $E,$ as shown in the figure. Its bob has mass $m$ and charge $q.$ The time period of the pendulum is given by:

In an electron gun,the electrons are accelerated by the potential $V$. If $e$ is the charge and $m$ is the mass of an electron,then the maximum velocity of these electrons will be

$A$ moving charge will gain energy due to the application of