Give reason : ''If net flux assocaited with closed surface is zero, then net charge enclosed by that surface is zero''.
The law implies that the total electric flux through a closed surface is zero if no charge is enclosed by the surface.
The electric field is uniform and we are considering a closed cylindrical surface with its axis parallel to the uniform field $\overrightarrow{\mathrm{E}}$.
$\phi_{1}$ and $\phi_{2}$ represent the flux through the surfaces $1$ and $2$ of the cylinder and $\phi_{3}$ is the flux through the curved cylindrical part of the closed surface.
Now the normal to the surface $3$ at every point is perpendicular to $\vec{E}$ so by definition of flux, $\phi_{3}=0$.
Further, the outward normal to $2$ is along $\vec{E}$ while the outward normal to $1$ is opposite to $\vec{E}$,
Hence, $\phi_{1}=-\mathrm{ES}_{1}=-\mathrm{ES} \quad\left(\because \mathrm{S}_{1}=\mathrm{S}\right)$
$\phi_{2}=\mathrm{ES}_{2}=\mathrm{ES} \quad\left(\because \mathrm{S}_{2}=\mathrm{S}\right)$
where $\mathrm{S}$ is the area of circular cross-section.
Thus, the total flux is zero, the total charge contained in the closed surface is zero.
$q_1, q_2, q_3$ and $q_4$ are point charges located at point as shown in the figure and $S$ is a spherical Gaussian surface of radius $R$. Which of the following is true according to the Gauss's law
A long cylindrical shell carries positive surface charge $\sigma$ in the upper half and negative surface charge $-\sigma$ in the lower half. The electric field lines around the cylinder will look like figure given in : (figures are schematic and not drawn to scale)
Electric lines of force about negative point charge are
The electric field in a region is radially outward with magnitude $E = A{\gamma _0}$. The charge contained in a sphere of radius ${\gamma _0}$ centered at the origin is
The circular wire in figure below encircles solenoid in which the magnetic flux is increasing at a constant rate out of the plane of the page. The clockwise emf around the circular loop is $\varepsilon_{0}$. By definition a voltammeter measures the voltage difference between the two points given by $V_{b}-V_{a}=-\int \limits_{a}^{b} E \cdot d s$ We assume that $a$ and $b$ are infinitesimally close to each other. The values of $V_{b}-V_{a}$ along the path $1$ and $V_{a}-V_{b}$ along the path $2$ , respectively are