(B)1.6×10⁻¹⁹
(C) 2.99×10⁹
(D) -1.6×10⁻¹⁹
Ans:- (A)
Q.2. Permittivity of free space is
(A) 9×10⁹ mF⁻¹
(B) 1.6×10⁻¹⁹C
(C) 8.85×10⁻¹²Fm⁻¹
(D) 8.85×10⁻⁹Fm⁻¹
Ans:- (C)
Q.3. The unit of electric field intensity is
(A) NC (Newton Coloumb)
(B) NC⁻¹ (Newton/Coloumb)
(C) Vm (Volt m)
(D) CN⁻¹ (Coloumb/Newton)
Ans:- (B)
Q.4. 1 Statcoulomb equals….coulomb.
A.3×10⁹
B.3×10⁻⁹
C.1/3×10⁹
D.1/3×10⁻⁹
Ans:- (D)
Q.5.The number of electrons that should be removed from an uncharged body to have a charge of one coloumb is
A.6.25×10¹⁸
B.6.25×10⁸
C.6.023×10²³
D.None of these
Ans:- (A)
Q.6. Electrostatic field is
(A) conservative
(B) non-conservative
(C) somewhere conservative and somewhere non-conservative
(D) None of these
Ans:- (A)
Q.7. Charges A and B attract each other. Charges B and C attract each other. Then A and C.
(A) will attract each other
(B) repel each other
(C) will not effect each other
(D) A , B and C
Ans:- (D)
Q.8. 1 Coulomb charge is equal to
A.3×10⁹ e.s.u.
B.9×10⁹ e.s.u.
C.8.85×10⁻¹² e.s.u.
D.None of these
Ans:- (A)
Q.9. The charge on a body is written as Q=ne whose e=1.6×10⁻¹⁹ C. The value n will be
A.0,1,2,3….
B.0, ±1, ±2, ±3 , ….
C.0,-1,-2,-3,…
D.None of these
Ans:- (B)
Q.10.Force between two charged particles situated at a distance is r. If distance between the two is made half, then the value of electric force will be
(A) 4 F
(B) 2 F
(C) 1/4 F
(D) 1/2
Ans:- (A)
Q.11. Coloumbian force is
(A) Central force
(B) Electric force
(C) Both a and b
(D) None of these
Ans:- (C)
Q.12. The charge on any substance can not be less than
(A) 1.6×10⁻¹⁹C
(B) 3.2×10⁻¹⁹C
(C) 4.8×10⁻¹⁹
(D) 1C
Ans:- (A)
Q.13. When a body is charged ,its mass
(A) Increases
(B) Decreases
(C) Remains same
(D) May increase or decrease
Ans:- (D)
Q.14. The dimensional formula of electric field intensity is
(A) [MLT⁻²A⁻¹]
(B) [MLT⁻³A⁻¹]
(C)ML²T⁻³A⁻²]
(D) [ML²T²A²]
Ans:- (B)
Q.15. Which of the laws gives the force between two charges at rest ?
(A) Gauss theorem
(B) Kirchhoff’s rules
(C) Coulomb’s law
(D) Faraday’s laws
Ans:- (C)
Q.16. The value of 1/4πε₀ is
(A) 9×10⁹ Nm²C⁻²
(B) 8.85×10⁻¹² Nm²C⁻²
(C) 9×10⁻⁹ Nm²C⁻²
(D) zero
Ans:- (B)
Q.17. There are two identical spheres A and B. A is given +Q charge and B is given -Q charge
(A) Mass of A increases
(B) Mass of B increases
(C) No effect on Mass
(D) None
Ans:- (B)
Q.18. The S.I. unit of electric flux is
(A) Weber
(B) Nm²C⁻¹
(C) Newton/m
(D) m²/s
Ans:- (B)
Q.19. The total charge on a electric dipole is
(A) Zero
(B) Negative
(C) Positive
(D) Infinite
Ans:- (A)
Q.20. The electric field intensity at infinite distance from an electric charge is
(A) Infinite
(B) Zero
(C) 9×10⁹V/m
(D) None of these
Ans:- (B)
Q.21. Unit of surface density of charge is
(A) Coulomb/meter²
(B) Newton meter⁻¹
(C) Coulomb Volt⁻¹
(D) Coulomb meter
Ans:- (A)
Q.22. The electric field at a point near an infinite thin sheet of charged conductor is
(A) ∈₀σ
(B) σ/∈₀
(C) σ/2∈₀
(D) σ∈₀/2
Ans:- (C)
Q.23. A surface encloses an electric dipole. The total electric flux over the surface is
(A) Infinite
(B) Zero
(C) q/∈₀
(D) None of these
Ans:- (B)
Q.24. When a soap bubble is charged, its radius
(A) Increases
(B) Decreases
(C) Remains the same
(D) Becomes zero
Ans:- (A)
Q.25. The electric field intensity inside a hollow spherical charged conductor is
(A) Infinite
(B) Zero
(C) Positive and greater than 1
(D) None
Ans:- (B)
Q.26. When a body becomes negatively charged, its mass
(A) Decreases
(B) Increases
(C) Remains the same
(D) None of these
Ans:- (B)
Q.27. The value of electric field inside a charged spherical conductor is
(A) σ/∈₀
(B) zero
(C) ∈₀σ
(D) σ²/∈₀
Ans:- (B)
Q.28. Minimum number of capacitors of 2μF each required to obtain a capacitance of 5μF will be
(A) 4
(B) 3
(C) 5
(D) 6
Ans:- (A)
Q.29. Surface charge density of a conductor is σ. Electric field near it is
(A) σ/2∈₀
(B) σ/∈₀
(C) 2σ/∈₀
(D) σ/3∈₀
Ans:- (B)
Q.30. Force of attraction between the plates of a parallel plate capacitor is
(A) -q²/2∈₀Ak
(B) q³/2∈₀A
(C) q/∈₀Ak
(D) q²/2∈₀A²k
Ans:- (A)