The electric field in a region is given by $\overrightarrow{ E }=\frac{2}{5} E _{0} \hat{ i }+\frac{3}{5} E _{0} \hat{ j }$ with $E _{0}=4.0 \times 10^{3}\, \frac{ N }{ C } .$ The flux of this field through a rectangular surface area $0.4 \,m ^{2}$ parallel to the $Y - Z$ plane is ....... $Nm ^{2} C ^{-1}$
$624$
$661$
$620$
$640$
If the electric field intensity in a fair weather atmosphere is $100 \,V / m$, then the total charge on the earth's surface is ............ $C$ (radius of the earth is $6400\,km$ )
An electric dipole is put in north-south direction in a sphere filled with water. Which statement is correct
Choose the incorrect statement :
$(a)$ The electric lines of force entering into a Gaussian surface provide negative flux.
$(b)$ A charge ' $q$ ' is placed at the centre of a cube. The flux through all the faces will be the same.
$(c)$ In a uniform electric field net flux through a closed Gaussian surface containing no net charge, is zero.
$(d)$ When electric field is parallel to a Gaussian surface, it provides a finite non-zero flux.
Choose the most appropriate answer from the options given below
A field line shown in the figure. This field line cannot represent
An infinite, uniformly charged sheet with surface charge density $\sigma$ cuts through a spherical Gaussian surface of radius $R$ at a distance $x$ from its center, as shown in the figure. The electric flux $\Phi $ through the Gaussian surface is