A charge $+q$ is situated at a distance $d$ away from both the sides of a grounded conducting $L$ shaped sheet as shown in the figure.The force acting on the charge $+q$ is
towards $O$, magnitude $\frac{q^2}{32 \pi \varepsilon_0 d^2}(2 \sqrt{2}+1)$
away from $O$, magnitude $\frac{q^2}{32 \pi \varepsilon_0 d^2}(2 \sqrt{2}+1)$
towards $O$, magnitude $\frac{q^2}{32 \pi \varepsilon_0 d^2}(2 \sqrt{2}-1)$
away from $O$, magnitude $\frac{q^2}{32 \pi \varepsilon_0 d^2}(2 \sqrt{2}-1)$
A thin metallic wire having cross sectional area of $10^{-4} \mathrm{~m}^2$ is used to make a ring of radius $30 \mathrm{~cm}$. A positive charge of $2 \pi \mathrm{C}$ is uniformly distributed over the ring, while another positive charge of $30$ $\mathrm{pC}$ is kept at the centre of the ring. The tension in the ring is__________ $\mathrm{N}$; provided that the ring does not get deformed (neglect the influence of gravity). (given, $\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \mathrm{SI}$ units)
Two identical conducting spheres carrying different charges attract each other with a force $F$ when placed in air medium at a distance $'d'$ apart. The spheres are brought into contact and then taken to their original positions. Now the two spheres repel each other with a force whose magnitude is equal to that of the the initial attractive force. The ratio between initial charges on the spheres is
Two charges placed in air repel each other by a force of ${10^{ - 4}}\,N$. When oil is introduced between the charges, the force becomes $2.5 \times {10^{ - 5}}\,N$. The dielectric constant of oil is
The magnitude of electric force on $2\, \mu \,C$ charge placed at the centre $O$ of two equilateral triangles each of side $10 \,cm$, as shown in figure is $P$. If charge $A, B, C, D, E$ and $F$ are $2\, \mu \,C, 2\, \mu \,C, 2\, \mu \,C,-2\, \mu \,C, -2\, \mu \,C, -2\, \mu \,C$ respectively, then $P$ is :.....$N$
Two point charges $Q$ each are placed at a distance $d$ apart. A third point charge $q$ is placed at a distance $x$ from mid-point on the perpendicular bisector. The value of $x$ at which charge $q$ will experience the maximum $Coulomb's force$ is ...............