# Gauss's Law and its Applications : Important Objective Questions

Provided below is an updated list of important objective questions from the chapter Gauss's Law and its Applications from board exams point of view. Students preparing for 12th board exams are advised to practice these set of questions (after properly going through the respective theoretical sections) in order to strengthen the conceptual grasp and score the highest in objective section of the actual physics paper.

All the questions given below are 12th board level objective type questions with single option correct.

1. The intensity of electric field due to a point charge Q at a distance r from it is given by (k = 1/4πϵₒ):

B) kQ/r²
C) kQr²
D) kQ²/r

2. Electric flux through a closed surface is 'x' times the net charge enclosed by the surface. Value of 'x' is equal to:
A) 1/ε₀
B) ε₀
C) 4πε₀
D) 1/4πε₀

3. The electric field intensity at a point lying inside a charged spherical shell (conducting) is
A) ε₀σ
B) σ/ε₀
C) zero
D) ε₀/2

4. At a point lying just outside of a charged conductor, the intensity of electric field is 1/ε₀ times the surface charge density where ε₀ is the permittivity of free space. This statement is called

B) Coulomb's Theorem
C) Gauss's Theorem
D) None of these

5. Electric field at a distance r from the axis of a infinitely long charged cylindrical conductor is
A) λ/πε₀r
B) λ/2πε₀r
C) λ/4πε₀r
D) λ/r

6. The direction of electric field vector at a point lying on the surface of a charged conductor is
A) zero
B) normal to the surface
C) tangential to the surface
D) at an angle of 45° from the surface

7. The permittivity of free space is

B)1.6 × 10⁻¹⁹ C
C) 8.85 × 10⁻¹² F/m
D) None of these.

8. Coulomb's Force is
A) Central Force
B) Electric Force
C) Conservative Force
D) All of the above

9. Which of the following charges cannot exit individually

B) 6.4 × 10⁻¹⁹ C
C) 2.4 × 10⁻¹⁹ C
D) 1.6 × 10⁻¹⁹ C

10. If the separation between two point charges is halved, then the force between them will get

B) one-fourth
C) doubled
D) None of these

11. Say the force between two point charges separated by a distance r is F. Now if the values of charges are doubled and the separation r is halved, then the electrostatic force will become

B) 4F
C) 16F
D) 64F

12. A static electric charge produces

B) electric field only
C) magnetic and electric fields both
D) Neither electric nor magnetic field

13. SI unit of electric field is

B) newton(N)
C) volt(V)
D) newton per coulomb (N/C)

14. SI unit of electric flux is
A) V m
B) V/m
C) N/m
D) None of these