Objective Questions on Electrostatic Field

Objective Questions on Electrostatic Field

Objective Questions on Electrostatic Field, MCQ on electric charges and fields, MCQ on electrostatics, electric field multiple-choice question ans answer.

Multiple Choice Questions

1. The proportionality constant in Coulomb’s law has unit of

• Farads
• Farads/meter
• Newton
• meter/Farad

Answer: meter/Farad

2. The value of proportionality constant in Coulomb’s law is

• 9 × 10⁹
• 9 × 10^–9
• 8.854 × 10^–12
• 1/36 π × 10⁹

Answer: 9 × 10⁹

3. The force magnitude between Q₁ = 1C and Q₂ = 1C when they are separated by 1 m in free space is

• 9 × 10⁹ N
• 8.854 × 10^–12 N
• 1/36 π × 10^-9 N
• 9 × 10^–9 N

Answer: 9 × 10⁹ N

4. Potential has the unit of

• Joules/Coulomb
• Joules
• Joules/m³
• Joules/m²

Answer: Joules/Coulomb

5. The unit of electric flux is

• Coulomb
• Coulomb/metre
• Weber
• Weber/m²

Answer: Coulomb

6. The unit of electric field is

• Newton
• Coulomb/Newton
• Newton/Coulomb
• Coulomb/metre

Answer: Newton/Coulomb

7. Potential at all the points on the surface of a conductor is

• the same
• not the same
• zero
• infinity

Answer: the same

8. Gradient of the potential and an equipotential surface

• have the same direction
• have opposite directions
• are orthogonal to each other
• have no directional relation

Answer: are orthogonal to each other

9. The Laplacian operator, ∇²

• has unit of m²
• is a vector operator
• has unit of 1/m²
• has no unit

Answer: has unit of 1/m²

10. Laplace’s equation has

• two solutions
• infinite solutions
• no solution
• only one solution

Answer: only one solution

11. The surface charge density in a good dielectric is

• zero
• ρ_s
• infinity
• – ρ_s

Answer: zero

12. Gauss’s law in point form is

• \bigtriangledown .D=\rho _{\upsilon }
• \bigtriangledown .D=\rho _{s}
• \bigtriangledown .D=Q
• \bigtriangledown D=\rho _{\upsilon }

Answer: \bigtriangledown .D=\rho _{\upsilon }

13. Poisson’s equation is

• \bigtriangledown ^{2}V=\rho _{\upsilon}/\epsilon
• \bigtriangledown ^{2}V=-\rho _{\upsilon}/\epsilon
• \bigtriangledown ^{2}V=-\rho _{\upsilon}
• \bigtriangledown ^{2}V=-\dot{\rho _{\upsilon}}/\epsilon

Answer: \bigtriangledown ^{2}V=-\rho _{\upsilon}/\epsilon

14. Electric flux lines

• originate at (+)ve charge
• originate at (–)ve charge
• are closed loops
• originate at (+)ve charge and also terminate at (+)ve charge

Answer: originate at (+)ve charge

15. Unit of electric flux is

• Coulomb
• Weber
• Tesla
• Weber/m

Answer: Coulomb