# Class 12 Physics Chapter 1 Electric Charges and Fields MCQs

CBSE Class 12 Physics Chapter 1 Electric Charges and Fields MCQs. These MCQs of Electric Charges and Fields chapter are prepared by our Physics Expert. By practising following MCQs, students will be able to quickly revise all the concepts of the chapter.

Additionally, these MCQs of Electric Charges and Fields will be helpfull for JEE And NEET Aspirants. These MCQs on Electric Charges and Fields chapter are prepared as per the latest curriculum issued by the CBSE.

### CBSE Class 12 Physics Chapter 1 Electric Charges and Fields MCQs

1. An infinite line charge produces a
field of 18 × 10^9 𝑁/𝐶 at 0.02 𝑚𝑚. The linear
charge density is
(A) 2 × 10^−7𝐶/𝑚
(B) 10^−8 𝐶/ 𝑚
(C) 2 × 10^−2𝐶/𝑚
(D) 10^−4 𝐶/𝑚

2. The S.I. unit of electric flux is
(A) Weber
(B) Newton per coulomb
(C) Volt /metre
(D) Joule per coulomb

3. If the radius is doubled, then, find the outward electric flux will , if a charge Q is enclosed by a Gaussian spherical surface of radius R.
(A) Be doubled
(B) Increase four times
(C) Be reduced to half
(D) Remain the same

4.What is the field at the centre of ring of radius R
carrying a charge q uniformly distributed over it?
(A) Kq/R
(B) 0
(C) 2Kq/R
(D) 2KqR

5. The electric charge in uniform motion produces
(A) An electric field only
(B) A magnetic field only
(C) Both electric and magnetic field
(D) Neither electric nor magnetic field

6. A body can be negatively charged by
(A) Giving excess of electrons to it
(B) Removing some electrons from it
(C) Giving some protons to it
(D) Removing some neutrons from it
Answer: Giving excess of electrons to it

7. An attractive force between two neutrons is due to
(A) Electrostatic and gravitational
(B) Electrostatic and nuclear
(C) Gravitational and nuclear
(D) Some other forces like Vander Waals

8. The law, governing the force between electric
charges is known as
(A) Ampere’s law
(B) Ohm’s law
(D) Coulomb’s law

9. Three charges 4 q, Q and q are in a straight line in
the position of O, l/2 and l respectively. The
resultant force on q will be zero, if Q is
(A) – q
(B) –2q
(C) q
(D) 4q

10. Two charges +q and +4q are placed ‘L’ distance apart. Where should we keep a third charge on the line joining +q
and +4q , so that the third charge is in equilibrium.
(A) L/9 from q towards 4q
(B) L/9 from 4q towards q
(C) L/3 from q towards 4q
(D) L/3 from 4q towards q
Answer: L/3 from q towards 4q

11. Four equal point charges each ‘q’ are placed on the four corners of a square of side ‘a’. Calculate the force on any one
of the charges.
(A) 𝑲𝒒^
𝟐/
𝒂^𝟐
(2+√2)
(B) 𝑲𝒒^𝟐/𝒂^𝟐
(2+1/√2)
(C) 𝑲𝒒^𝟐/𝒂^𝟐(√2+1/2)
(D) None of these

12. If mass of electron is m and charge on electron is –e. To balance the
weight of electron , find the intensity of Electric field
(A) 0
(B) Mg/e
(C) 𝟐𝒎𝒈/𝒆
(D) 𝐊

13. Find the location of third charge on the line joining +q
and –9q, where it will remain in equilibrium.
(A) 1/2 from q
(B) 1/2 from –9q
(C) 1/4 from q
(D) -1/4 from -9q

14. The electric flux through each face of the cube is _____, If a charge Q is placed at the corner of a cube
[MORE THAN ONE CORRECT]
(A) 𝟑𝐐/
∈𝐨
(B) 𝟐𝟒/
𝐐∈𝐨
(C) 𝐐
/𝟖∈𝐨
(D) 0

15. The electric flux through all the six faces of the cube is , if a charge Q is placed at the corner of a cube.
(A) 0
(B) 𝟐𝟒/𝐐∈𝐨
(C) 𝐐/𝟖∈𝐨
(D) ∈𝐐/𝐊

16. If electric field, flux through a closed surface
is zero.
[MORE THAN ONE
CORRECT]
(A) The electric field must be zero everywhere on the surface.
(B) The electric field may be zero everywhere on the surface.
(C) The charge inside the surface must be zero.
(D)None