Question 11.1: What is the magnitude of the force of attraction between an iron nucleus bearing charge q=26e and its innermost electron, if the distance between them is 1×10^-12m.

Question 11.2: charges 2μC, -3μC, and 4μC are placed in air at the vertices of an equilateral triangle of sides 10 cm. What is the magnitude of resultant force acting on 4μC charge?

Question 11.3: A charge q is placed at the center of the line joining the two charges. each of magnitude Q. Prove the the system of three charges will be in equilibrium if q=-Q/4.

Question 11.4: Two equal and opposite charges of magnitude 2×10^-7C are placed 15cm apart. What is magnitude and direction of electric intensity (E) at a point mid -way between the charges? What force would act on a proton (Charge = +1.6×10^-19C) placed there?

Question 11.5: Two positive point charges of 15 X 10^-10C and 13 x 10^-10C are placed 12cm apart. Fine the work done in bringing the two charges 4cm closer.

Question 11.6: A hollow sphere is charged to 14μC. Find the potential (a) at its surface (b) inside the sphere (c) at a distance of 0.2m from the surface. The radius of sphere is 0.3m.

Question 11.7: if 280J of work is done in carrying a charge of 2C from a place where the potential is -12V to another place where potentional is V, calculate the value of V.

Question 11.8: Calculate the electric potential at the surface of a silver nucleus having radius 3.4 x 10^-14m. The atomic number of silver is 47 and charge on a proton = 1.6 x 10^-19C.

Question 11.9: The electric field at a point due to a point charge is 25 N/C and the electric potential at that point is 13J/C. calculate the distance of the point from the charge and magnitude of charge.

Question 11.10: Two point charges of 8μC and -4μC are separated by a distance of 10cm in air. At what point on the line joining the two charges is the electric potential zero.