A cathode ray tube contains a pair of parallel metal plates $1.0\, cm$ apart and $3.0\, cm$ long. A narrow horizontal beam of electron with a velocity $3 \times 10^7\, m/s$ passed down the tube midway between the plates. When a potential difference of $550\, V$ is maintained across the plates, it is found that the electron beam is so deflected that it just strikes the end of one of the plates. Then the specific charge of the electron in $C/kg$ is
$1.8 \times 10^9$
$1.8 \times 10^{10}$
$1.8 \times 10^{11}$
$1.8 \times 10^{12}$
The figure gives the electric potential $V$ as a function of distance through five regions on $x$-axis. Which of the following is true for the electric field $E$ in these regions
What is potential gradient ?
At a certain distance from a point charge the electric field is $500\,V/m$ and the potential is $3000\,V$. What is this distance......$m$
Two plates are at potentials $-10\, V$ and $+30\, V$. If the separation between the plates be $2\, cm$. The electric field between them is.......$V/m$
If on the $x$-axis electric potential decreases uniformly from $60 \,V$ to $20 \,V$ between $x=-2 \,m$ to $x=+2 \,m$, then the magnitude of electric field at the origin