When the distance between the charged particles is halved, the force between them becomes

The force between two charges $0.06\,m$ apart is $5\,N$. If each charge is moved towards the other by $0.01\,m$, then the force between them will become.........$N$

A charge of $Q$ coulomb is placed on a solid piece of metal of irregular shape. The charge will distribute itself

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

A proton is fired at an initial velocity of $150 \,m/s$ at an angle of $60^o $ above the horizontal into a uniform electric field of $2 \times 10^{-4} \,N/C$ between two charged parallel plates as shown in figure. Then the total time the particle is in motion is :-

A particle of mass $1 \,{mg}$ and charge $q$ is lying at the mid-point of two stationary particles kept at a distance $'2 \,{m}^{\prime}$ when each is carrying same charge $'q'.$ If the free charged particle is displaced from its equilibrium position through distance $'x'$ $(x\,< \,1\, {m})$. The particle executes $SHM.$ Its angular frequency of oscillation will be $....\,\times 10^{8}\, {rad} / {s}$ if ${q}^{2}=10\, {C}^{2}$