1. ELECTRIC CHARGES AND FIELDS ( Objective Question Answer 2022 )

1. Which one of the following is the unit of electric field ?
(A) Coulomb
(B) Newton
(C) Volt
(D) N/C
Answer тЗТ D |
2. If an electric dipole is kept in a uniform electric field then resultant electric force on it is :
(A) always zero
(B) never zero
(C) depend upon capacity of dipole
(D) None
Answer тЗТ A |
3. The number of electron taken out from a body to produce 1 coulomb of charge will be:
(A) 6.25 x 1018
(B) 6.25 x 108
(C) 6.023 x 1023
(D) None
Answer тЗТ A |
4. The work done in rotating an electric dipole in an electric field :
(A) W = ME (1 – cos╬╕)
(B) W = ME tan╬╕
(C) W = ME sec╬╕
(D) None
Answer тЗТ A |
5. If sphere of bad conductor is given charge then it is distributed on :
(A) surface
(B) inside the surface
(C) only inside the surface
(D) None
Answer тЗТ D |
6. Electric field in a cavity of metal :
(A) depends upon the surroundings
(B) depends upon the size of cavity
(C) is always zero
(D) is not necessarily zero
Answer тЗТ D |
7. The dielectric constant of a metal is :
(A) O
(B) 1
(C) тИЮ
(D) -1
Answer тЗТ C |
8. I coulomb is equal to :
(A) 3 x 109 e.s.u.
(B) 1/3 x 109 e.s.u.
(C) 3 x 1010 e.s.u.
(D) 1/3 x 1010 e.s.u.
Answer тЗТ A |
9. Each of the two point charges are doubled and their distance is halved. Force 77 interaction becomes p times, where p is :
(A) 1
(B) 4
(C) 1/16
(D) 16
Answer тЗТ D |
10. Coulomb’s law in vector form can be written as :
where ╬╡0 is the permitivity of free space. The SI units of ╬╡0 will be :
(A) N-1 m-2 C-2
(B) N m-2 C2
(C) N-1 m-2 C2
(D) N m-2 C2
Answer тЗТ C |
11. The dimensional representation of eреж will be:
(A) [MLT4 A2]
(B) [M-1 L-3 T4 A2]
(C) [ML-2 T2 A-2]
(D) None of these
Answer тЗТ B |
12. When placed in a uniform field, a dipole experiences :
(A) a net force
(B) a torque
(C) both a net force and torque
(D) neither a net force nor a torque
Answer тЗТ B |
13. A parrot comes and sits on a bare high power line. It will :
(A) experience a mild shock.
(B) experience a strong shock.
(C) get killed instantaneously.
(D) not be affected practically.
Answer тЗТ D |
14. The SI units of electric dipole moment are :
(A) C
(B) Cm-1
(C) Cm
(D) Nm-1
Answer тЗТ C |
15. If two conducting sphere are connected after charging separately then :
(A) Electrostatic energy sphere energy wil remain conserved
(B) Electrostatic energy charges remains conserved
(C) Electrostatic energy energy and charge remains conserved
(D) None
Answer тЗТ B |
16. A semicircular arc of radius r is charged uniformly and the charge per unit length is ╬╗ The electric field at the centre is :
Answer тЗТ B |
17. When a dipole of moment тАЭ p is placed in uniform electric field e, then the torque acting on the dipole is :
Answer тЗТ C |
18. The graph drawn between V are r for a non-conducting charged solid sphere of radius R for r<R will be :
(A) straight line
(B) parabola
(C) hyperbola
(D) None of these
Answer тЗТ D |
19. Corona discharge takes place :
(A) at the surface of a conductor
(B) near the sharp points of a conductor
(C) outside the conductor
(D) at the centre of the conductor
Answer тЗТ B |
20. The belt of a Vande Graaf generator gets charge by :
(A) corona discharge
(B) induction
(C) electrification
(D) None of these
Answer тЗТ A |
21. Quantisation of charge implies :
(A) Charge does not exist
(B) Charge exists on particles
(C) There is a minimum permissible magnitude of charge
(D) Charge can’t be created
Answer тЗТ C |
22. The conservation of electric charge implies that :
(A) Charge can’t be created
(B) Charge can’t be destroyed
(C) The number of charged particle in the universe is constant
(D) Simultaneous creation of equal and opposite charges is permissible
Answer тЗТ D |
23. The number of electrons contained in one coulomb of charge is :
(A) 6.25 x 1018
(B) 6.25 x 1017
(C) 6.25 x 1019
(D) 1.6 x 1019
Answer тЗТ A |
24. The unit of intensity of electric field is :
(A) metre/volt
(B) Joule/newton
(C) Coulomb/newton
(D) Newton/coulomb
Answer тЗТ A |
25. 1 V equals to :
(A) 1 J
(C) 1 JC-1
(C) 1 CJ-1
(D) 1 JC
Answer тЗТ B |
26. 1 Vm-1 equals to :
(A) 1 N
(B) 1 Mm-1
(C) 1 NC-1
(D) 1 J-1
Answer тЗТ C |
27. The minimum amount of charge observed so far is :
(A) 1 C
(B) 4.8 x 1-13 C
(C) 1.6 ├Ч 10-19 C
(D) 1.6 x 1019 C
Answer тЗТ C |
28. The ratio of electric force between two electrons to the gravitational force between them is of the order :
(A) 1042
(B) 1039
(C) 1036
(D) 1
Answer тЗТ A |
29. A spherical equipotential surface is not possible :
(A) for a point charge
(B) for a dipole
(C) inside a uniformly charged sphere
(D) inside a spherical conductor
Answer тЗТ B |
30. Charge on one proton in Coulomb is :
(A) 1.6 x 10-19
(B) 9.1 x 10-31
(C) тАУ 1.6 x 10-19
(D) None of these
Answer тЗТ A |
31. The energy density at a point in vacuum where the electric field is E, will be :
Answer тЗТ C |
32. Electric field intensity at the centre of an electric dipole of length 2d is :
Answer тЗТ B |
33. Electric field due to a solid non-conducting sphere inside varies as :
Answer тЗТ A |
34. Ratio of electric fields due to an electric dipole on its axis and on the perpendicular bisector of the dipole at the same distance is :
(A) 4:1
(B) 1:4
(C) 2:1
(D) 1:2
Answer тЗТ C |
35. SI unit of dielectric constant is :
(A) NM-2 C-2
(B) NM-2 C2
(C) No unit
(D) F/N
Answer тЗТ C |
36. A point charge +q is placed at the mid-point of a cube of side a. The electric flux emerging from a cube is :
Answer тЗТ C |
37. A charge Q is placed at the mouth of a conical flask. The flux of the electric field through the flask is :
Answer тЗТ C |
38. A long string with charge per unit length ╬╗ passes through an imaginary cube of edge’a’. The maximum flux of electric field through the cube will be:
Answer тЗТ D |
Class 12th physics objective question in English
S.N | Physics Objective English Medium |
1. | ┬аELECTRIC CHARGES AND FIELDS |
2. | LECTROSTATIC POTENTIAL AND CAPACITANCE |
3. | CURRENT ELECTRICITY |
4. | MOVING CHARGES AND MAGNETISM |
5. | MAGNETISM AND MATTER |
6. | ELECTROMAGNETIC INDUCTION |
7. | ALTERNATING CURRENT |
8. | ELECTROMAGNETIC WAVES |
9. | RAY OPTICS AND OPTICAL INSTRUMENTS |
10. | WAVE OPTICS |
11. | DUAL NATURE OF MATTER AND RADIATION |
12. | ATOMS |
13. | NUCLEI |
14. | SEMI CONDUCTOR ELECTRONICS┬а |
15. | COMMUNICATION SYSTEMS |