Three-point charges are arranged, as shown in Figure. What is their mutual potential energy? Take $q=1.0\times {10}^{-4}C$ and $a=10 \mathrm{cm}.$

  

Determine the potential energy of the charge configuration shown in Figure.

Find the amount of work done in arranging the three-point charges, on the vertices of an equilateral triangle $ABC,$of side $10 \mathrm{cm},$as shown in the adjacent figure.

Calculate the work done to dissociate the system of three charges placed on the vertices of a triangle, as shown in Fig. 2.38. Here $q=1.6\times {10}^{-10}C.$

What is the electrostatic potential energy of the charge configuration shown in Figure?

Take $q_1=+ 1.0\times {10}^{-8} \mathrm{C}, q_2=- 2.0\times {10}^{-8}\mathrm{ }\mathrm{C},q_3=+ 3.0\times {10}^{-8} C,q_4=+ 2.0\times {10}^{-8}\mathrm{ }\mathrm{C}$ and $a=1.0$metre.

Three-point charges $+ q,+2q$ and $Q$ are placed at the three vertices of an equilateral triangle. Find the value of charge $Q$ (in terms of  $q$), so that electric potential energy of the system is zero.

 An electron (charge $=-e$) is placed at each of the eight corners of a cube of side $a$and an $\alpha$-particle (charge $=+2e$) at the centre of the cube. Calculate the potential energy of the system.

[3 Marks]

Two identical particles, each having a charge of $2.0\times {10}^{-4}\mathrm{ }\mathrm{C}$ and mass of $10\mathrm{ }\mathrm{g}$, are kept at a separation of $10 \mathrm{cm}$ and then released. What would be the speeds of the particles when the separation becomes large?

Find the amount of work done in rotating an electric dipole, of dipole moment $3.2\times {10}^{-8}\mathrm{ }\mathrm{Cm}$. from its position of stable equilibrium to the position of unstable equilibrium, in a uniform electric field of intensity ${10}^4\mathrm{ }\mathrm{N}/\mathrm{C}.$