1: What is the magnitude of the force of attraction between an iron nucleus bearing charge q = 26e and its inner most electron, if the distance between them is 1ｘ10⁻¹² m. (Answer 6 ｘ10⁻³ N)
(Click for verified Solution)



2: Charges 2 µC, -3 µC, and 4 µC are placed in air at the vertices of an equilateral triangle of sides 10 cm. What is the magnitude of resultant force acting on 4 µC charge? (Answer 15.7 N)



3: Two equal and opposite charges of magnitude 2 ｘ10⁻⁷ C are placed 15 cm apart. What is the magnitude and direction of electric intensity (E) at a point midway between the charges? What force would act on a proton (charge = +1.6 ｘ 10⁻¹⁹ C) placed there? (Answer 0.64 ｘ 10⁶ N/C along AB, 1.024 ｘ 10 ⁻¹³ N along AB)

4: Two positive point charges of 15 ｘ 10⁻¹⁰ C and 13 ｘ10⁻¹⁰ C are placed 12 cm apart. Find the work done in bringing the two charges 4 cm closer. (Answer 7.31 ｘ 10⁻⁸ J)

5: A hollow sphere is charged to 14 µC. Find the potential (a) at its surface (b) inside the sphere (c) at a distance of 0.2m from the surface. The radius of the sphere is 0.3m. (Answer 42 ｘ 10⁴ V, 42 ｘ 10⁴ V, 25.2 ｘ 10⁴ V)

6: If 280 J of work is done in carrying a charge of 2 C from a place where the potential is -12 V to another place where potential is V, calculate the value of V. (Answer 128 V)



7: The electric field at a point due to a point charge is 26 N/C and the electric potential at that point is 13 J/C. Calculate the distance of the point from the charge and magnitude of charge. (Answer 0.722 ｘ 10⁻⁹ C)

(Click for verified Solution)



8: Two point charges of 8 µC and -4 µC are separated by a distance of 10 cm in air. At what point on the line joining the two charges is the electric potential zero? (Answer 6.6 cm from 8 µC and, 3.3 cm from -4 µC charge)



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