$q_1, q_2, q_3$ 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
$\oint\limits_s {\left( {{{\vec E}_1} + {{\vec E}_2} + {{\vec E}_3}} \right).d\overrightarrow A = \frac{{{q_1} + {q_2} + {q_3}}}{{2\,{ \in _0}}}}$
$\oint\limits_s {\left( {{{\vec E}_1} + {{\vec E}_2} + {{\vec E}_3}} \right).d\overrightarrow A = \frac{{{q_1} + {q_2} + {q_3}}}{{{ \in _0}}}} $
$\oint\limits_s {\left( {{{\vec E}_1} + {{\vec E}_2} + {{\vec E}_3}} \right).d\overrightarrow A = \frac{{{q_1} + {q_2} + {q_3} + {q_4}}}{{{ \in _0}}}} $
None of the above
An electric field converges at the origin whose magnitude is given by the expression $E = 100\,r\,Nt/Coul$, where $r$ is the distance measured from the origin.
A charge $+q$ is placed somewhere inside the cavity of a thick conducting spherical shell of inner radius $R_1$ and outer radius $R_2$. A charge $+Q$ is placed at a distance $r > R_2$ from the centre of the shell. Then the electric field in the hollow cavity
A square surface of side $L$ meter in the plane of the paper is placed in a uniform electric field $E(volt/m)$ acting along the same plane at an angle $\theta$ with the horizontal side of the square as shown in figure.The electric flux linked to the surface, in units of $volt \;m $
Using thomson's model of the atom, consider an atom consisting of two electrons, each of charge $-e$, embeded in a sphere of charge $+2e$ and radius $R$. In equilibrium each electron is at a distance $d$ from the centre of the atom. What is the equilibrium separation between electrons
Two charged thin infinite plane sheets of uniform surface charge density $\sigma_{+}$ and $\sigma_{-}$ where $\left|\sigma_{+}\right|>\left|\sigma_{-}\right|$ intersect at right angle. Which of the following best represents the electric field lines for this system