Electrostatics question bank (Physics)

Three particles, each having a charge of $10 \mu \mathrm{C}$ are placed at the corners of an equilateral triangle of side 10 cm. The electrostatic potential energy of the system is $\left(\right.$ Given $\left.\frac{1}{4 \pi \varepsilon_{0}}=9 \times 10^{9} \mathrm{~N}-\mathrm{m}^{2} \mathrm{C}^{2}\right)$

Two charge metallic spheres are joined by a very thin metal wire. If the radius of the larger sphere is four times that of the smaller sphere, the electric field near the larger sphere is