Sample Page /10 12345678910 Quiz-1: Electric Charges and Electric Field 1 / 10 The force $F$ between charges $Q_1$ and $Q_2$ separated by distance $r$ is $25N$. If the force reduces to $5N$, the separation between them is $\frac{r}{\sqrt{5}}$ $2r$ $\frac{r}{2}$ $\sqrt{5}r$ 2 / 10 Due to a point charge at the centre of a spherical Gaussian surface of diameter $a$, $10^6 Nm^2/C$ amount of electric flux passes through it. Keeping the point charge at the centre, the Gaussian surface is changed to a cubical Gaussian surface of side $a$. The flux through the new Gaussian surface will be $\sqrt{2}\times 10^6 Nm^2/C$ $ 10^6 Nm^2/C$ $2\sqrt{2}\times 10^6 Nm^2/C$ $10^6 /\sqrt{2} Nm^2/C$ 3 / 10 The law regarding the electrostatic force between two-point charges is Coulomb's law Ampere's law Gauss's law Faraday's law 4 / 10 The unit of electric permittivity in SI system is $N m/{C^2}$ $N m^2/{C^2}$ $C^2/{N m^2}$ $C/{N m^2}$ 5 / 10 The dimension of electric permitivity is $[M^{-1} L^3 T^4 A^{2}]$ $[M^{-1} L^{-3} T^4 A^{2}]$ $[M L^{-3} T^4 A^{2}]$ $[M L^3 T^4 A^{-2}]$ 6 / 10 The dimension of electric flux is $[M L T^{-2}A]$ $[M^{-1} L^{-1} T^{3}A]$ $[M L^{3} T^{-3}A^{-1}]$ $[M^{2} L T^{-2}A^{-2}]$ 7 / 10 The value of $\frac{1}{4\pi\epsilon_0}$ in SI unit is $9\times 10^9 N m C^{-2}$ $10^9 N m^2 C^{-2}$ $9\times 10^9 N m^2 C^{-2}$ $9\times 10^9 N m C^{-1}$ 8 / 10 The -ve and +ve charge of a dipole of dipole moment $\vec{p}$ are placed respectively at points $-\hat{i}a$ and $+\hat{i}a$. If $y>>a$, then the electric field intensity due to the dipole at the point located at $\hat{j}y$, is $-\frac{\vec{p}}{2\pi\epsilon_0 y^3}$ $\frac{\vec{p}}{4\pi\epsilon_0 y^3}$ $-\frac{\vec{p}}{4\pi\epsilon_0 y^3}$ $\frac{\vec{p}}{2\pi\epsilon_0 y^3}$ 9 / 10 The magnitude of force experienced by an electron placed at a point in the electric field $\vec{E}$ equals its weight $m\vec{g}$. The magnitude of $\vec{E}$ is ${mg}/e^2$ ${mg}/e$ $mge$ $e/{mg}$ 10 / 10 The ratio of the electric field intensity due to an electric dipole at an axial point to that at an equatorial point at the same distance from the centre is $1:2$ $1:1$ $2:1$ $1:4$ Your score is 0% Restart quiz