Electrostatic Potential and Capacitance Mock Test – Class 12 Physics

1. Inside a conductor in electrostatic equilibrium, the electric field is:

2. In a parallel combination of capacitors, the quantity common to all capacitors is:

3. For a dipole made of charges and separated by distance , the dipole moment is:

4. During a closed-loop motion, a charge is moved slowly in an electrostatic field and brought back to its starting point. The total work done by the electrostatic field is:

5. Two charges are kept fixed while their separation changes from to . If their initial potential energy is , the final potential energy is:

6. A -versus- graph is drawn for a capacitor of fixed capacitance . The graph is:

7. A capacitor is kept connected to a battery. Its capacitance without dielectric is . After a dielectric is fully inserted, its capacitance becomes . The increase in charge on the plates is:

8. Equipotential surfaces of different potential values cannot intersect because:

9. In the definition of electrostatic potential, the test charge is specified as a positive test charge mainly so that:

10. Assertion: A negative charge can lose potential energy while moving from a lower potential to a higher potential.
Reason: For a negative charge, decreases when increases.

11. A parallel-plate capacitor has plate area and separation . A dielectric slab of thickness and dielectric constant fills the full plate area. The capacitance becomes:

12. A -versus- graph for a capacitor has slope . The same capacitor is charged to . Its stored energy is:

13. The electric field just outside a conductor is , directed outward normal to the surface. The local surface charge density is:

14. The action of sharp points in a Van de Graaff generator is useful because:

15. The row that pairs a quantity with its SI unit is:

16. A student’s claim says: “If the potential at a point is zero, the electric field at that point must also be zero.” The best response is:

17. A slow movement of charge is considered between two points in an electrostatic field. Why is the idea of work useful before introducing detailed formulas?

18. The row that correctly describes stored energy when capacitance changes is:

19. A graph is described as follows.

What physical conclusion follows from this reference-level change?

20. A conductor in electrostatic equilibrium has a cavity containing no charge. The statement that best describes the potential inside the cavity is:

21. The capacitance of an isolated spherical conductor of radius in vacuum is:

22. A conductor is in electrostatic equilibrium. The potential throughout its volume and surface is:

23. A capacitor remains connected to a battery while a dielectric of constant is fully inserted. If the initial stored energy is , the final energy stored in the capacitor is:

24. A positive charge is moved from point to point , both lying on the same equipotential surface. The electric field may be non-zero along the region, yet the electrostatic work is zero because:

25. Two charges and are placed in a pre-existing external potential field. If the external potentials at their locations are and , the energy of the two charges in that external potential is:

26. A charged conducting shell has a point charge kept inside its closed cavity without touching the shell. In electrostatic equilibrium, the net charge induced on the inner surface of the cavity is:

27. A neutral hollow conductor contains a charge inside its cavity. The charges induced on the inner and outer surfaces of the conductor are:

28. The maximum potential of a Van de Graaff dome in air is limited mainly by:

29. For capacitors connected in series, the equivalent capacitance satisfies:

30. Match the work or energy expression with its meaning for movement from to .

31. Identify the properly classified set of quantities.

32. A particle with charge moves from to in a region where . The work done by the electric field is:

33. Two cases are described for the same parallel-plate capacitor.

The correct comparison is:

34. Two unlike charges are slowly separated from distance to . If their initial potential energy is , the final potential energy is:

35. The claim “If is large at a point, then must also be large at that point” is best evaluated as:

36. For a dielectric-filled parallel-plate capacitor with plate area , separation , and dielectric constant , its capacitance is:

37. Use the graph description below.

The energy stored in the capacitor is represented by:

38. The statement in electrostatics expresses that:

39. Three point charges , , and are fixed at the corners of an equilateral triangle of side . A charge is slowly brought from infinity to the centroid of the triangle. If the distance of each corner from the centroid is , the external work required is:

40. In using for charges in an external field, the potential should be:

41. A point is at distances , , and from charges , , and , respectively. The net potential at is, taking :

42. For a negative point charge, potentials are measured at distances and . If the potential at is , the potential at is:

43. A basic capacitor consists of two conducting plates separated by an insulating medium. When the capacitor is charged from an initially neutral state, the plates usually carry:

44. A dielectric slab of dielectric constant completely fills the space between the plates of a parallel-plate capacitor. The capacitance becomes:

45. Charges and are placed at two points where the external potentials are and , respectively. The energy of these charges in the external potential is:

46. A record shows that of external work is needed to bring a small positive test charge of from the reference point to a point . The electrostatic potential at is:

47. For two points and , the potential difference is best interpreted as:

48. Three statements about a Van de Graaff generator are given.
I. Charge delivered to the dome resides on its outer surface.
II. The dome potential rises as more charge is accumulated.
III. The belt must be a good metal conductor for charge transport.

49. For a point charge , points and are at distances and , respectively. If for a positive source charge, the potential is:

50. Three charges , , and are placed at the corners of an equilateral triangle of side . The total electrostatic potential energy is: