Ch 1. Electric Charges And Fields

Question 1

The ratio of electric force and gravitational force acting between two charges is in the order of

Answer 1

10⁴²

Question 2

A charge ‘q’ placed at the centre on the line joining two charges ‘Q’ will be in equilibrium if ‘q’ will be equal to

Answer 2

-Q/4

Question 3

What is the angle between the electric dipole moment p and the electric field strength E when the dipole is in a stable equilibrium

Answer 3

0 Degrees

Question 4

Which of the following physical quantities is a vector?

Answer 4

Electric intensity

Question 5

The law, governing the force acting between two electric charges known as

Answer 5

Coulomb’s Law

Question 6

S.I unit of permittivity is

Answer 6

Farad per meter (F/m)

(C²N⁻¹m⁻²)

Question 7

The total electric flux coming out from stationary unit positive charge in air is

Answer 7

ε₀⁻¹

The symbol ε₀ represents the permittivity of free space. It’s a constant used in electromagnetism and its value is approximately 8.85 x 10^-12 Farad per meter (F/m). The symbol “⁻¹” denotes the inverse or reciprocal of a quantity. So, ε₀⁻¹ means the reciprocal of the permittivity of free space

Question 8

The force, acting on per unit charge is called

Answer 8

Electric field

Question 9

Quantization of charge indicates that

Answer 9

Charge, which is a fraction of charge on an electron, is not possible

Question 10

Electric field lines provide information about

Answer 10

Field strength, direction and nature of charge

Question 11

The value of 1/4πε₀ is

Answer 11

9 × 10⁹ Nm² c⁻²

Question 12

Which of the following relation is correct

Answer 12

E= F/q

Arrow sign on E and F

Question 13

SI unit of electric dipole moment is

Answer 13

The SI unit for electric dipole moment is the coulomb-meter (C⋅m)

Question 14

The relative permittivity (εr) of a medium is

Neeche r

Answer 14

ε/ε₀

Question 15

Surface density of a charge is equal to

Answer 15

Total Charge/Total Area

Question 16

The dielectric constant of water is

Answer 16

80

Question 17

The value of force acting on a charged particle in electric field is

Answer 17

qE

Question 18

Which of the following values of n is not possible in relation Q = ne?

Answer 18

4.2

Question 19

The value of ε, in air is

Answer 19

1

Question 20

Dimension of charge is

Answer 20

AT

Question 21

Which of the following has unit volt/metre?

Answer 21

Electric Field

Question 22

Unit of ε₀ is

Answer 22

Fm⁻¹

Question 23

Unit of surface charge density is

Answer 23

Coulomb/metre²

Question 24

In the figure, if net force on Q is zero then the value of Q/q is

Answer 24

2√2

Question 25

When a body is charged, it’s mass —

Answer 25

May increases or decreases

Question 26

The torque acting on electric dipole of dipole moment P placed in electric field of intensity E is

Answer 26

p × E

Question 27

The electric dipole moment of an electric dipole made up of two opposite charge having magnitude +3.2 × 10⁻¹⁹C and -3.2 × 10⁻¹⁹C separated by a distance 2.4 × 10⁻¹⁰ m is

Answer 27

7.68 × 10⁻²⁹ C-m

Question 28

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

Answer 28

Perpendicular to the surface

Question 29

Permittivity of the free space is

Answer 29

8.85 × 10⁻¹² Fm⁻¹

Question 30

What is the SI unit of electric dipole moment?

Answer 30

Coulomb- metre

Question 31

The SI unit of electric field E is

Answer 31

NC⁻¹

Question 32

1 stat-coulomb = ……… Coulomb

Answer 32

1/3 × 10⁻⁹

Question 33

1 coulomb charge = …… e.s.u

Answer 33

3 × 10⁹

Question 34

The specific charge of electron is

Answer 34

1.8 × 10¹¹ C/kg

Question 35

Electrostatic field is

Answer 35

Conservative

Question 36

Which is scalar quantity?

Answer 36

Charge, Capacitance and Potential

Question 37

Intensity of electric field at a point is

Answer 37

E = F/q

Question 38

Surface density of charge is

Answer 38

σ = Q/A or σ = dq/dA

Question 39

The vector form of Coulomb’s law is

Question 40

Which of the following is correct for charge on an electron?

Answer 40

e = 1.602 × 10⁻¹⁹ C

Question 41

The SI unit of electric intensity is

Answer 41

Newton per Coulomb (N/C) Or Volt per meter (V/m).

Question 42

S.I unit of electric flux is

Answer 42

Volt-metre

Question 43

If + q charge is placed inside any spherical surface then total flux coming out from whole surface will be

Answer 43

q/ε₀

Question 44

The electric field at a point near an infinite thin sheet of charged conductor is

Answer 44

E = σ/2ε₀

Question 45

The electrical intensity inside a charged holllow sphere is

Answer 45

Zero

Question 46

The electric flux over the surface of a sphere if it is charged with 10µC is

Answer 46

36π × 10⁴ Nm²/C