Electrostatic Potential and Capacitance Mock Test – Class 12 Physics

1. The same network from the previous question is connected across an battery: and are in parallel, and that group is in series with . The charge on the series branch is:

2. The best reason why excess charge on an isolated conductor resides on its outer surface is:

3. A capacitor is charged by a source from to final charge . The -versus- graph is a straight line through the origin. If the final values are and , the stored energy is:

4. The energy stored in a parallel-plate capacitor can be connected to field energy density using , , and . The result for energy per unit volume is:

5. A dipole has moment . A far point is at and from . Taking , the approximate potential is:

6. Assertion: The torque on a dipole in a uniform electric field is maximum at .
Reason: At , the potential energy of the dipole is minimum.

7. A claim says: “If the electrostatic force is conservative, then a charge cannot gain kinetic energy in an electric field.” The best evaluation is:

8. The statement in electrostatics expresses that:

9. Assertion: No work is done by the electrostatic field when a charge moves along an equipotential surface.
Reason: Along an equipotential surface, the potential difference between any two points is zero.

10. Three statements about equipotential surfaces are listed.
I. is perpendicular to an equipotential surface.
II. Closer equipotential surfaces indicate a stronger electric field for the same potential difference.
III. A charge moving along an equipotential surface always has maximum change in potential energy.

11. In moving from point to point , the displacement has two parts: along a uniform field of , followed by perpendicular to the field. The total potential change is:

12. Assertion: Inserting a dielectric fully between the plates of a parallel-plate capacitor increases its capacitance.
Reason: The dielectric reduces the effective field for the same free charge, so a smaller potential difference is produced for that charge.

13. A graph is drawn for the potential due to a positive point charge as distance from the charge increases from a small positive value to a very large value. The graph should:

14. A negative value of electrostatic work is mentioned while discussing movement of a charge. The sign most directly means that:

15. At any point on an equipotential surface, the electric field is directed:

16. A graph is described as follows.

What physical conclusion follows from this reference-level change?

17. The row that correctly compares potential and electric field due to a point charge is:

18. The work done by a battery in charging a capacitor to and is , while the capacitor stores only . This difference occurs because:

19. A capacitor of capacitance carries charge . Its stored energy is:

20. Capacitors connected in series have the same:

21. In calculating the electrostatic potential energy of a system of point charges, the term should be counted:

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

23. Assertion: A dipole placed at in a uniform electric field is in unstable equilibrium.
Reason: At , has its maximum value.

24. 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?

25. The graph description below refers to a negative point charge.

The slope of this graph is:

26. A comparison of distance dependence for dipole quantities is given. The supported row is:

27. The graph of versus for two unlike charges, with at infinity, is best described as:

28. A closed conducting box is used to protect a sensitive device from an external electrostatic field. The protection works because:

29. A dielectric is inserted into an isolated capacitor and is pulled in by the electric field. The decrease in stored electrostatic energy mainly appears as:

30. A capacitor is charged from a battery of voltage through ordinary connecting wires. The energy supplied by the battery and the energy finally stored in the capacitor are:

31. Assertion: The equivalent capacitance of capacitors in series is less than the smallest individual capacitance.
Reason: In series, the reciprocal capacitances add.

32. If a air capacitor is completely filled with a dielectric of constant , its new capacitance is:

33. For slow movement of a charge in an electrostatic field, the external work is equal to:

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

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

36. A capacitor and an capacitor are connected in series across a battery. The battery is then disconnected, and a dielectric of constant is fully inserted into the capacitor only. The new total potential difference across the series combination is:

37. For a slow movement from to , the relation that correctly connects field work and potential energy is:

38. Assertion: In electrostatics, work done in moving a charge slowly between two fixed points does not depend on the path followed.
Reason: The work can be expressed through the potential difference between the endpoints.

39. Three statements about electrostatic work are given.
I. for motion from to .
II. for slow motion from to .
III. Over a closed path, electrostatic field work is zero.

40. The one-dimensional relation between electric field and potential variation along the -axis is:

41. Assertion: A conductor can shield its empty cavity from an external electrostatic field.
Reason: In electrostatic equilibrium, charges on the conductor redistribute so that the electric field inside the conducting material is zero.

42. An electric dipole consists of charges and separated by . At a point , the distances from and are and , respectively. The potential at is:

43. Three statements are made about potential energy in electrostatics.
I. For a single charge in an external potential, .
II. For two point charges, their mutual energy is .
III. For many point charges, every distinct pair contribution is counted twice.

44. At two corners of an equilateral triangle of side , charges and are fixed. At the third corner, the potential is:

45. In a closed path in an electrostatic field, a charge returns to its starting point. The potential difference for the complete round trip is:

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

47. A metal sphere is charged and then left undisturbed. The potential at any two points on its surface is:

48. A dipole in a uniform electric field has , where is the angle between and . Its potential energy is:

49. Several capacitors are connected in parallel. The equivalent capacitance is:

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