1. A closed surface has a net flux of 6.78 × 10^5 Nm²/C. What is the charge enclosed?

2. A uniform field E = 7 × 10^3 N/C is along the z-axis. What is the flux through a circle of radius 25 cm in the xy-plane?

3. A charge of 11 µC is at the center of a cube of edge 45 cm. What is the total flux through the cube?

4. A glass rod loses 6.4 × 10^-8 C of charge when rubbed with silk. How many electrons were transferred from it?

5. Three charges +8 μC, -4 µC, +2 µC are at the vertices of an equilateral triangle of side 1.8 m. What is the force magnitude on +8 µC?

6. Which principle underlies the fact that the electric field due to a system of charges can be analyzed by considering each charge independently?

7. Two charges +5 µC and – 7 µC are 35 cm apart. What is the electric field magnitude at the midpoint?

8. Why does the electric field due to a uniformly charged infinite plane remain unaffected by the distance from the plane?

9. A thin spherical shell of radius 22 cm has q = 15 µC. What is the electric field at 26 cm from the center?

10. Three equal charges q = 3 µC are at the vertices of an equilateral triangle of side 1 m. What is the electric field at the centroid?

11. Two point charges -3 × 10^-7 C and 5 × 10^-7 C are 80 cm apart in vacuum. What is the magnitude of the force between them?

12. A dipole with charges 4 µC and -4 µC separated by 2 mm is in a field 7 × 10^4 N/C at 30 deg. What is the torque?

13. A dipole with moment p = 5 × 10^-9 Cm is at 60 deg to a uniform field E = 4 × 10^4 N/C. What is the torque magnitude?

14. A dipole with p = 7 × 10^-9 Cm is at 45 deg to a field E = 4 × 10^4 N/C. What is the torque?

15. What explains why the electric field due to a dipole can be zero at certain points along its equatorial plane?