Which graph shows variation of electric field of a uniformly charged sphere $w.r.t.$ distance $(r)$ from the centre
A parallel plate capacitor has plates with area $A$ and separation $d$ . A battery charges the plates to a potential difference $V_0$. The battery is then disconnected and a dielectric slab of thickness $d $ is introduced. The ratio of energy stored in the capacitor before and after the slab is introduced is
A negative charged particle is released from rest in a uniform electric field. The electric potential energy of charge
A particle of charge $Q$ and mass $m$ travels through a potential difference $V$ from rest. The final momentum of the particle is
In the given circuit if point $C$ is connected to the earth and a potential of $+2000\,V$ is given to the point $A$ , the potential of $B$ is.....$V$
Four charges equal to $-Q$ are placed at the four corners of a square and a charge $q$ is at its centre. If the system is in equilibrium, the value of $q$ is