Point charges q,-q,2Q and Q are placed in order at the corners A,B,C,D of a square of side 2b. If the field at the midpoint of CD is zero then q/Q is?

a)1

b)2

c)2 root2/5

d)5 root5/2

Electrostatics question based on earthing of spherical shell

an object has a charge of 2c and gains 10^19 electrons. the net chaarge on the object becomes??

A wire with a linear charge density lambda forms a quarter of a cjrclenof radius R and is placed asa shown in thefigure with its centre of curvature at the origin O the electric field at O will be

Find the value of q so that system remains in equilibrium.. figure attached below

Need to find the time taken for the dipole to come back to eqm