Two point charges $$\mathrm{M}$$ and $$\mathrm{N}$$ having charges $$+q$$ and $$-q$$ respectively are placed at a distance apart. Force acting between them is $$\mathrm{F}$$. If $$30 \%$$ of charge of $$\mathrm{N}$$ is transferred to $$\mathrm{M}$$, then the force between the charges becomes:

If 216 drops of the same size are charged at $$200 \mathrm{~V}$$ each and they combine to form a bigger drop, the potential of the bigger drop will be

Three point charges are located on a circular arc at $$\mathrm{A}, \mathrm{B}$$ and $$\mathrm{C}$$ as shown in the figure below. The total electric field at the centre of the $$\operatorname{arc}(\mathrm{C})$$ is

A square shaped aluminium coin weighs $$0.75 \mathrm{~g}$$ and its diagonal measures $$14 \mathrm{~mm}$$. It has equal amounts of positive and negative charges. Suppose those equal charges were concentrated in two charges $$(+Q$$ and $$-Q)$$ that are separated by a distance equal to the side of the coin, the dipole moment of the dipole is