A neutral water molecule is placed in an electric field $$E=2.5 \times 10^4 \mathrm{NC}^{-1}$$. The work done to rotate it by $$180^{\circ}$$ is $$5 \times 10^{-25} \mathrm{~J}$$. Find the approximate separation of centre of charges.

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