Electric Field and Electric Charge MCQ Questions CDPs

CDP 120101

  1. If a system contains two point charges q1 and q2 , the total charge of the system is obtained simply by adding algebraically q1 and q2 . e.g., (– 2 units charge) + (6 units charge) = 4 units charge.

          II.  (– 2 units charge) + (6 units charge) = 8 units charge.

          III. Charge has magnitude but no direction, similar to mass.

          IV. Mass of a body is always positive whereas a charge can be either positive    or negative.

          Incorrect statement is

          (a) only I        (b) only III

          (c) only IV      (d) only II

2. If a body gives out 109 electrons per second, how much time is required to get a total charge of 1 C from it?

          (a) Around 200 min. (b) Around 200 hours

          (c) Around 200 days  (d) Around 200 years

3. For 250 ml water in a cup, positive charge and negative charge in water, are respectively

          (a) 1.34 × 10–7 C, – 1.34 × 10–7 C

          (b) 1.34 × 107 C, –1.34 × 107 C

          (c) 1.34 × 107 C, –1.34 × 10–7 C

          (d) 1.34 × 10–7 C, –1.34 × 107 C

4. Intensity of an electric field E due to a dipole, depends on distance r as

          (a)                 (b)

          (c)                 (d)

5. The surface considered for Gauss’s law is called
(a) Closed surface
(b) Spherical surface
(c) Gaussian surface
(d) Plane surface

6. Which of the following statements is not true about Gauss’s law?
(a) Gauss’s law is true for any closed surface.
(b) The term q on the right side side of Gauss’s law includes the sum of all charges enclosed by the surface.
(c) Gauss’s law is not much useful in calculating electrostatic field when the system has some symmetry.
(d) Gauss’s law is based on the inverse square dependence on distance contained in the coulomb’s law

7. The force per unit charge is known as
(a) electric flux
(b) electric field
(c) electric potential
(d) electric current

8. Electric field lines provide information about
(a) field strength
(b) direction
(c) nature of charge
(d) all of these

9. Which of the following figures represent the electric field lines due to a single negative charge?

10. The SI unit of electric flux is
(a) N C-1 m-2
(b) N C m-2
(c) N C-2 m2
(d) N C-1 m2

11. The unit of electric dipole moment is
(a) newton
(b) coulomb
(c) farad
(d) debye

12. Consider a region inside which, there are various types of charges but the total charge is zero. At points outside the region
(a) the electric field is necessarily zero.
(b) the electric field is due to the dipole moment of the charge distribution only.
(c) the dominant electric field is inversely pro-portional to r3, for large r (distance from ori-gin).
(d) the work done to move a charged particle along a closed path, away from the region will not be zero.

13. SI unit of permittivity of free space is

    (a) Farad

    (b) Weber

    (c) C2 N-1 m-2

    (d) C2 N-1 m-1

    14. Which of the following is false about Electrostatic field lines?

    1. Field lines start from positive charges and end at negative charges.
    2. If there is a single positive charge, field lines will end at infinity.
    3. Two field lines can never cross each other
    4. Electrostatic field lines form closed loops.

    15. The magnitude of electric force experienced by a charged particle in an electric field depends on:

    1. charge of the particle
    2. the velocity of the particle
    3. the direction of the electric field
    4. mass of the particle

    16. The intensity of the electric field at any point on the surface of a charged conductor is 

    1. zero
    2. perpendicular to surface
    3. tangential to surface
    4. infinite

    17. In an electric field E directed downwards a proton of charge e will experience a _.

    1. the upward force of magnitude eE
    2. the downward force of magnitude e/E
    3. the upward force of magnitude e/E
    4. the downward force of magnitude eE

    18. The SI unit of the electric field is:

    1. Cm-2
    2. Am-1
    3. Vm-1
    4. Cm-1

    19. A body is positively charged, which implies that

    1. There is only a positive charge in the body.
    2. there is positive as well as negative charge in the body but a positive charge is more than a negative charge
    3. there is equally positive and negative charge in the body but the positive charge lies in the outer regions
    4. the negative charge is displaced from its position

    20. When a glass rod is rubbed with silk, it

    • gives electrons to silk.
    • gives protons to silk.
    • gains electrons from silk.
    • gains protons from silk.

    CDP 120102

    1. In general, metallic ropes are suspended on the carriers taking inflammable materials. The reason is
    1. to keep the centre of gravity of the carrier nearer to the earth.
    2. to control the speed of the carrier.
    3. to keep the body of the carrier in contact with the earth.
    4. none of the above

    2. quantization of charge indicates that

    1. Charge, which is a fraction of charge on an electron, is not possible
    2. A charge cannot be destroyed
    3. Charge exists on particles
    4. There exists a minimum permissible charge on a particle

    3. A force F acts between two charges +Q and -Q that is placed at a certain distance from each other. The third sphere of charge Q is placed between them. What is the magnitude and force experienced by the third charge?

    • 3F in the direction of +Q charge
    • 4F in the direction of +Q charge
    • 8F in the direction of -Q charge
    • No direction and magnitude is zero

    4. At a distance r, two equal charges are kept and they exert a force F on each other. What is the force acting on each charge, if the distance between them is doubled and charges are halved?

    • F/4
    • 4 F
    • F/16
    • F/8

    5. Pick the true statements about electric field lines

    • It provides information about the direction of the electric field
    • Electric field lines provide information about the type of charge
    • Electric field lines provide information about the field strength
    • All of the above

    6. The variation of electric field E due to a hollow spherical conductor of radius R as a function of distance from the centre of the sphere is shown in which of the following graphs?

    •                                                       (c)
    •                                                      (d)          

    7. Which of the following material is not an insulator?

    • Dry air    (b) Diamond   (c ) Ebonite    (d) Human Body

    8. Electricity produced on rubbing is

    • Static electricity (b) Electromagnetism  (c) Current electricity  (d) None of the above

    9. When two bodies are rubbing against each other, they acquire

    • Equal and similar charges
    • Equal and opposite charges
    • Unequal and similar charges
    • Unequal and opposite charges

    10. Objects may acquire an excess or deficiency of charges by

    1. Hammering
    2. Heating
    3. Shaking
    4. Rubbing

    11. A method of charging a conductor without bringing a charged body in contact with it is called

    1. Magnetization
    2. Electrification
    3. Electrostatic Induction
    4. Electromagnetic induction

    12. The electrostatic attracting force on a small sphere of charge 0.2 µC due to another small sphere of charges -0.4µC in air is 0.4N. The distance between the two spheres is

    1. 43.2 ×10-6m
    2. 42.4 ×10-3m
    3. 18.1 ×10-3m
    4. 19.2 ×10-6m

    13. Which of the following represent the electric lines of forces between two negative charges

      1. What is the dimensional formula of electric flux
      2. [M L2 T-2 A2]
      3. [M L3 T-3 A-1]
      4. [M L3 T-2 A-1]
      5. [M L-3 T-2 A-1]

      14. What is the dimensional formula of electric force

      1. [M L T-2 A0]
      2. [M L2 T A2]
      3. [M L T-2 A]
      4. [M L2 T-2 A2]

      15. What is the dimensional formula of permittivity of the medium

      1. [M-1 L T-2 A0]
      2. [M L2 T A2]
      3. [M L T-4 A]
      4. [M-1 L-3 T4 A2]

      16. A uniformly charged conducting sphere of 4.4 m diameter has a surface charge density of 60µC m-2. The charge on the sphere is

      1. 7.3 ×10-3C
      2. 3.7 ×10-3C
      3. 7.3 ×10-6C
      4. 3.7 ×10-6C

      17. Assertion:- When a body acquires a negative charge, its mass decreases

        Reason: – A body acquires negative charge when it losses electrons

        d

        18. Assertion: – Coulomb’s law and gravitational law follow the same inverse squire law.

          Reason: – Both laws are same in all aspects.

          c

          19. Assertion: – The whole charge of a conductor cannot be transferred to another isolated conductor.

          Reason: – The total transfer of charge from one to another is not possible.

          D