TRB BT Assistant - Electrostatics and Electric Fields Online Test (MCQ Quiz)

1. What is the fundamental unit of electric charge?

A) Electron B) Proton C) Coulomb D) Ampere

2. Which law states that the force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them?

A) Newton's Law of Gravitation B) Ampere's Law C) Faraday's Law D) Coulomb's Law

3. The force between two positive charges is:

A) Attractive B) Repulsive C) Neither attractive nor repulsive D) Zero

4. The force between a positive and a negative charge is:

A) Attractive B) Repulsive C) Neither attractive nor repulsive D) Zero

5. Electric field strength is defined as the force per unit:

A) Charge B) Mass C) Distance D) Energy

6. The unit of electric field strength is:

A) Newton/Coulomb B) Coulomb/Newton C) Volt/meter D) Both A and C

7. Electric field lines originate from positive charges and terminate on:

A) Positive charges B) Negative charges C) Neutral objects D) Conductors

8. Electric field lines never intersect because:

A) Electric field is always uniform B) A point cannot have two different electric field directions C) Electric field is always zero D) Charges repel field lines

9. What is the electric flux through a closed surface?

A) The net charge enclosed divided by the permittivity of free space B) The total charge enclosed C) The net electric field strength D) Zero, unless there is a charge inside

10. Gauss's Law relates the electric flux through a closed surface to the:

A) Surface area B) Net charge enclosed C) Electric field strength at the surface D) Volume enclosed

11. For a point charge 'q' at the center of a cube, the electric flux through one face of the cube is:

A) q / ε₀ B) q / (6ε₀) C) q / (4πε₀) D) Zero

12. In a conductor, under electrostatic conditions, the electric field inside the conductor is:

A) Maximum B) Minimum but not zero C) Zero D) Equal to the external field

13. In a conductor, under electrostatic conditions, the net charge resides:

A) Inside the conductor B) On the surface of the conductor C) Distributed uniformly throughout the volume D) Depends on the shape of the conductor

14. The potential difference between two points is the work done per unit charge to move a charge between those points:

A) Against the electric field B) Along the electric field C) Perpendicular to the electric field D) With zero acceleration

15. The unit of electric potential is:

A) Joule/Coulomb B) Coulomb/Joule C) Newton/Coulomb D) Volt/meter

16. Electric potential is a:

A) Scalar quantity B) Vector quantity C) Tensor quantity D) Complex quantity

17. The relationship between electric field (E) and electric potential (V) is given by:

A) E = -dV/dr B) E = dV/dr C) E = V * r D) E = V / r²

18. A region where a charged particle experiences a force due to the presence of other charges is called an:

A) Electric potential B) Electric field C) Electric flux D) Electric current

19. What is the electric field at the center of an electric dipole?

A) Zero B) Maximum C) Depends on the distance D) Infinite

20. What is the electric potential at the center of an electric dipole?

A) Zero B) Maximum C) Depends on the distance D) Infinite

21. An equipotential surface is a surface on which the electric potential is:

A) Uniformly increasing B) Uniformly decreasing C) Constant D) Zero

22. Electric field lines are always perpendicular to:

A) Conducting surfaces B) Equipotential surfaces C) Charged surfaces D) Neutral surfaces

23. A dipole consists of two:

A) Equal positive charges B) Equal negative charges C) Equal and opposite charges separated by a distance D) Unequal charges

24. The electric dipole moment is defined as the product of one charge and the:

A) Distance from the charge B) Distance between the charges C) Square of the distance D) Magnitude of the electric field

25. The unit of electric dipole moment is:

A) Coulomb-meter B) Newton-meter C) Joule-meter D) Volt-meter

26. The capacitance of a parallel plate capacitor is given by C = ε₀A/d, where A is the area of the plates and d is the distance between them. If d is doubled, the capacitance:

A) Doubles B) Halves C) Remains the same D) Quadruples

27. If a dielectric material is inserted between the plates of a parallel plate capacitor, its capacitance:

A) Decreases B) Increases C) Remains unchanged D) Becomes zero

28. The permittivity of free space (ε₀) is approximately:

A) 8.85 x 10⁻¹² C²/Nm² B) 9 x 10⁹ Nm²/C² C) 1.6 x 10⁻¹⁹ C D) 6.67 x 10⁻¹¹ Nm²/kg²

29. The electrostatic force between two charges is proportional to the inverse square of the distance between them. This is a statement of:

A) Gauss's Law B) Coulomb's Law C) Ohm's Law D) Faraday's Law

30. Which of the following is a vector quantity?

A) Electric potential B) Electric field strength C) Electric charge D) Capacitance

31. What is the electric field at a distance 'r' from an infinitely long uniformly charged wire with linear charge density λ?

A) λ / (2πε₀r) B) λ / (4πε₀r) C) 2πε₀r / λ D) 4πε₀r / λ

32. What is the electric field at a distance 'r' from the center of a uniformly charged spherical shell of radius R and total charge Q (for r > R)?

A) KQ/r² B) KQ/R² C) Zero D) KQR/r²

33. What is the electric field at a distance 'r' from the center of a uniformly charged solid sphere of radius R and total charge Q (for r < R)?

A) KQr/R³ B) KQ/r² C) Zero D) KQR/r²

34. The unit of electric flux is:

A) Newton-meter²/Coulomb B) Volt-meter C) Both A and B D) Coulomb/meter

35. If the electric field is uniform, the work done to move a charge between two points depends on:

A) The path taken B) The displacement between the points C) The charge of the particle D) The mass of the particle

36. Which statement is true regarding conductors in electrostatic equilibrium?

A) The electric field inside is non-zero. B) The net charge resides on the surface. C) The potential is constant throughout the volume. D) Charges are free to move anywhere within the conductor.

37. The capacitance of a spherical conductor of radius R is:

A) 4πε₀R B) 1/(4πε₀R) C) 4πε₀R² D) 1/(4πε₀R²)

38. What is the electrostatic potential energy of a system of two point charges q₁ and q₂ separated by a distance r?

A) kq₁q₂/r B) -kq₁q₂/r C) kq₁q₂r D) kq₁/r²

39. The force on a charge q in an electric field E is given by:

A) F = E/q B) F = q/E C) F = qE D) F = E/q²

40. A Van de Graaff generator produces:

A) High voltage, low current B) Low voltage, high current C) High voltage, high current D) Low voltage, low current

41. Electric field lines are denser where the electric field is:

A) Weaker B) Stronger C) Zero D) Uniform

42. What is the SI unit of electric current?

A) Volt B) Ohm C) Ampere D) Coulomb

43. The process of removing electrons from an atom or molecule is called:

A) Ionization B) Neutralization C) Conduction D) Polarization

44. What is the electric field at the surface of a conductor in electrostatic equilibrium?

A) Zero B) Perpendicular to the surface C) Parallel to the surface D) Depends on the interior field

45. If two equal positive charges are brought closer together, the potential energy of the system:

A) Increases B) Decreases C) Remains the same D) Becomes zero

46. The work done in moving a unit positive charge from infinity to a point in an electric field is equal to the:

A) Electric field strength at that point B) Electric potential at that point C) Electric flux at that point D) Force at that point

47. What is the dielectric constant of vacuum?

A) 0 B) 1 C) Infinity D) Depends on the field strength

48. The property of a material that opposes the formation of electric field lines within it is called:

A) Conductivity B) Permittivity C) Resistivity D) Permeability

49. Which of the following is conserved in all electrostatic interactions?

A) Electric potential B) Electric field C) Electric charge D) Electric flux

50. A point charge Q is placed at the origin. The electric flux through a closed surface that encloses the origin is independent of:

A) The magnitude of Q B) The permittivity of free space C) The shape and size of the closed surface D) The position of the charge within the surface

Electrostatics and Electric Fields - Online Test

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