Electric Charges and Fields

Class 12 Physics Chapter 1 Objective in English : Here you can find class 12th physics Objective questions for board exam 2023. Electric Charges and Fields objective questions is very important for board exam 2022 – 2023. mcq questions for class 12 physics chapter 1 in english. important question website

12th Physics Chapter 1 Objective Questions in English

  1. The minimum value of charge on any object cannot be less than

(a) 1.6 x 10-19 

(b) 3.2 x 10-19

(c) 4.8 x10-19

(d) 1C 

Answer (a) 1.6 x 10-19 

  1. The electric field intensity at distances r and 2r from a long, uniformly charged straight wire are E1or E2respectively. The ratio of E1 and E2 will be:

(a) 1/2 

(b) 2/1

(c) 1/1 

(d) None of these

Answer (b) 2/1

  1. At what angle do two electric field lines intersect each other?

(a) 90°

(b) 45°

(c) 30° 

(d) do not intersect

Answer (d) do not intersect

  1. The quantum of electric charge in e.s.u. is 

(a) 4.78 x 10-10

(b) +1.6 x 10-19

(c) 2.99 x 109

(d) –1.6 x 10-19

Answer (a) 4.78 x 10-10

  1. Electrostatic field is 

(a) conservative

(b) non-conservative

(c) somewhere conservative and somewhere non-conservative

(d) None of these 

Answer (a) conservative

  1. The specific charge of an electron is 

(a) 1.8 x 1011 C/kg

(b) 1.8 x 10-19 C/kg

(c) 1.9 × 10-19 C/kg

(d) none 

Answer (a) 1.8 x 1011 C/kg

  1. Debye is the unit of 

(a) charge 

(b) polarization

(c) electric dipole moment

(d) none 

Answer (c) electric dipole moment

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

(a) zero 

(b) perpendicular to the surface

(c) tangential to the surface

(d) at 45° to the surface 

Answer (b) perpendicular to the surface

  1. 1 coulomb charge is equal to 

(a) 2.99 x 109 e.s.u.

(b) 9 x 109 e.s.u.

(c) 8.85 x 10-12 e.s.u.

(d) none 

Answer (a) 2.99 x 109 e.s.u.

  1. An electric dipole is placed parallel to X-axis in an electric field. The force on it will be

(a) zero 

(b) normal to X-axis

(c) along X-axis

(d) None of these

Answer (d) None of these

  1. The unit of Electric susceptibility (χ) is 

(a) Nm-1

(b) Fm-1

(c) CV-1

(d) None of these 

Answer (b) Fm-1

  1. The unit of electric field intensity is 

(a) NC

(b) NC-1

(c) Vm

(d) CN-1

Answer (b) NC-1

  1. Which of the following is a vector? 

(a) charge 

(b) capacity

(c) electric field intensity

(d) None of these 

Answer (c) electric field intensity

  1. When a soap bubble is charged, its radius 

(a) increases 

(b) decreases

(c) remains the same

(d) becomes zero

Answer (a) increases 

  • The SI units of electric dipole moment are:

(a) C

(b) Cm-1

(c) Cm

(d) Nm-1

Answer (c) Cm

  1. If two conducting sphere are connected after charging separately then:

(a) Electrostatic energy sphere energy will remain conserved

(b) Electrostatic energy charges remains conserved

(c) Electrostatic energy energy and charge remains conserved

(d) None

Answer (b) Electrostatic energy charges remains conserved

  1. A soap bubble is given a negative charge, then its radius:

(a) increases

(b) decreases

(c) remains unchanged

(d) may increase or decrease

Answer (a) increases

  1. In non-uniform electric field, electric dipole experiences:

(a) torque only

(b) torque as well as net force

(c) force only

(d) None of these

Answer (b) torque as well as net force

  1. An electron is sent in an electric field of magnitude 9.1 × 106NC-1. The acceleration produced in it is :

(a) 1.6 ms-2

(b) 1.6 × 1018ms-2

(c) 3.2 × 1018ms-2

(d) 0.8 × 1018 ms-2

Answer (b) 1.6 × 1018ms-2

  1. A semicircular arc of radius r is charged uniformly and the charge per unit length is λ. The electric field at the centre is:

(a) λ/2λε0r2

(b) λ/4πε0r

(c) λ2/2πε0r

(d) λ/2πε0r

Answer (b) λ/4πε0r

  1. Two point charges +8q and -2q are located at ,v = O and ,v = L respectively. The location of a point on the .v-axis at which the net electric field due to these two point charges b is zero :

(a) 4L

(b) 8L

(c) L/4

(d) 2L

Answer (d) 2L

  1. 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 (d) None of these

  1. 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 (b) near the sharp points of a conductor

  1. The belt of a Vande Graaf generator gets charge by :

(a) corona discharge

(b) induction

(c) electrification

(d) None of these

Answer (a) corona discharge

  1. 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 (c) There is a minimum permissible magnitude of charge

  1. 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 (d) Simultaneous creation of equal and opposite charges is permissible

  1. The number of electrons contained in one coulomb of charge is:

(a) 6.25 × 1018

(b) 6.25 × 1017

(c) 6.25 × 1019

(d) 1.6 × 1019

Answer (a) 6.25 × 1018

  1. The unit of intensity of electric field is :

(a) metre/volt

(b) Joule/newton

(c) Coulomb/newton

(d) Newton/coulomb

Answer (a) metre/volt

  1. 1 V equals to:

(a) 1 J

(b) 1 JC-1

(c) 1 CJ-1

(d) 1 JC

Answer (b) 1 JC-1

  1. 1 V m-1equals to:

(a) 1 N

(b) 1 Mm-1

(c) 1 NC-1

(d) 1 J-1

Answer (c) 1 NC-1

  1. The minimum amount of charge observed so far is:

(a) 1 C

(b) 4.8 × 1-13 C

(c) 1.6 × 10-19 C

(d) 1.6 × 1019 C

Answer (c) 1.6 × 10-19 C

  1. 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 (a) 1042

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