Electrostatics and Electric Fields - Question Bank

1. 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
2. Which of the following is conserved in all electrostatic interactions?
A) Electric potential
B) Electric field
C) Electric charge
D) Electric flux
3. 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
4. What is the dielectric constant of vacuum?
A) 0
B) 1
C) Infinity
D) Depends on the field strength
5. 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
6. 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
7. 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
8. The process of removing electrons from an atom or molecule is called:
A) Ionization
B) Neutralization
C) Conduction
D) Polarization
9. What is the SI unit of electric current?
A) Volt
B) Ohm
C) Ampere
D) Coulomb
10. Electric field lines are denser where the electric field is:
A) Weaker
B) Stronger
C) Zero
D) Uniform
11. 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
12. 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
13. 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
14. The capacitance of a spherical conductor of radius R is:
A) 4πε₀R
B) 1/(4πε₀R)
C) 4πε₀R²
D) 1/(4πε₀R²)
15. 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.
16. 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
17. The unit of electric flux is:
A) Newton-meter²/Coulomb
B) Volt-meter
C) Both A and B
D) Coulomb/meter
18. 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
19. 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
20. 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
21. Which of the following is a vector quantity?
A) Electric potential
B) Electric field strength
C) Electric charge
D) Capacitance
22. 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
23. 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
24. 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
25. 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
26. The unit of electric dipole moment is:
A) Coulomb-meter
B) Newton-meter
C) Joule-meter
D) Volt-meter
27. 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
28. 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
29. Electric field lines are always perpendicular to:
A) Conducting surfaces
B) Equipotential surfaces
C) Charged surfaces
D) Neutral surfaces
30. An equipotential surface is a surface on which the electric potential is:
A) Uniformly increasing
B) Uniformly decreasing
C) Constant
D) Zero
31. What is the electric potential at the center of an electric dipole?
A) Zero
B) Maximum
C) Depends on the distance
D) Infinite
32. What is the electric field at the center of an electric dipole?
A) Zero
B) Maximum
C) Depends on the distance
D) Infinite
33. 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
34. 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
35. Electric potential is a:
A) Scalar quantity
B) Vector quantity
C) Tensor quantity
D) Complex quantity
36. The unit of electric potential is:
A) Joule/Coulomb
B) Coulomb/Joule
C) Newton/Coulomb
D) Volt/meter
37. 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
38. 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
39. 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
40. 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
41. 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
42. 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
43. 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
44. Electric field lines originate from positive charges and terminate on:
A) Positive charges
B) Negative charges
C) Neutral objects
D) Conductors
45. The unit of electric field strength is:
A) Newton/Coulomb
B) Coulomb/Newton
C) Volt/meter
D) Both A and C
46. Electric field strength is defined as the force per unit:
A) Charge
B) Mass
C) Distance
D) Energy
47. The force between a positive and a negative charge is:
A) Attractive
B) Repulsive
C) Neither attractive nor repulsive
D) Zero
48. The force between two positive charges is:
A) Attractive
B) Repulsive
C) Neither attractive nor repulsive
D) Zero
49. 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
50. What is the fundamental unit of electric charge?
A) Electron
B) Proton
C) Coulomb
D) Ampere