Electrostatics

Question 1

SI unit of electric charge

Answer 1

COULOMB (C)

Question 2

Properties of electric charge

Answer 2

1. Additivity of charge
2. Quantization
3. Conservation of charge
4. Auxiliary property of charge
   4.1. charge is always associated with matter
   4.2. Like charges repel and unlike charges attract
   4.3. Charge on a particle is independent of the state of rest or motion of the particle.

Question 3

What are the methods of charging a body?

Answer 3

1. By friction - for insulators
2. By conduction - for conductors
3. By Induction - for conductors

Question 4

What is Coulomb’s law?

Answer 4

Force on charge q by the charge Q = (kqQ)/r² where k is 1/4πε∘ and r is the distance between them.

Question 5

Value of K and ε∘ respectively

Answer 5

9 ⨉ 10⁹ Nm²/C² and 8.84 ⨉ 10⁻¹² C²N⁻¹m⁻² .

Question 6

Limitations of Coulomb’s law.

Answer 6

Only applicable on point charges placed on a large distance.

Question 7

What is central force?

Answer 7

magnitude depends on distance of the object from the origin. and directed along the line joining them.

Question 8

Formula of Electric Field.

Answer 8

F/q

Question 9

Direction of Electric Field

Answer 9

Away from positive charge and into negative charge.

Question 10

What is the direction of force on a +ve and -ve charge in an electric field?

Answer 10

Same direction for +ve and opposite for -ve.

Question 11

value of G

Answer 11

Approximately 6.674 x 10⁻¹¹ m³ kg⁻¹ s⁻²

Question 12

mass of electron

Answer 12

9.1 ⨉ 10⁻³¹ kg

Question 13

mass of proton

Answer 13

1.67 ⨉ 10⁻²⁷ kg

Question 14

Electric field due to a uniform charged ring

Answer 14