Chapter 1 Electric Charges And Fields

Question 1

What is an example of electric discharge?

Answer 1

Lightning during a thunderstorm

Question 2

Why do we experience an electric shock?

Answer 2

These experiences are due to discharge of electric charges caused due to their accumulation by rubbing of insulating surface.

Question 3

What do you mean by Statics?

Answer 3

Anything that does not move or change with time

Question 4

What does Electrostatics deal with?

Answer 4

It deals with forces, fields and potentials.

Question 5

Who discovered that amber rubbed with wool or silk attract light objects?

Answer 5

Thales of Miletus,Greece

Question 6

Electricity is coined from the word….

Answer 6

Elektron in Greek meaning amber

Question 7

After years of careful study, scientists found…

Answer 7

There are two types of entities called electric charge

Question 8

How can electrification occur?

Answer 8

On rubbing

Question 9

The pith ball experiment suggests two types of electrification, what are the conclusions?

Answer 9

Like charges repel
Unlike charges attract

Question 10

What is the property that differentiates two types of charges?

Answer 10

Polarity

Question 11

When two oppositely charged bodies are brought in contact, what happens.

Answer 11

The charges neutralize or nullify each other’s effect

Question 12

Benjamin Franklin named the charges as

Answer 12

Positive and Negative

Question 13

Glass rod and cat’s fur are

Answer 13

Positive

Question 14

Plastic rod and silk are

Answer 14

Negative

Question 15

When an object possess charge it is

Answer 15

Electrified

Question 16

When an object has no charge it is

Answer 16

Electrically neutral

Question 17

An apparatus used to detect the charge on the body

Answer 17

The gold leaf electroscope

Question 18

The amount of charge is indicated by

Answer 18

Degree of divergence

Question 19

All objects are electrically neutral, why?

Answer 19

They possess charges but they are equally balanced

Question 20

Forces holding molecules together, forces that hold atoms together in a solid, the adhesive force of glue, force associated with surface tension are

Answer 20

All electrical in nature, arising from the force between two charged particles.

Question 21

During rubbing….

Answer 21

No new charges are created

Question 22

The electrons transferred during rubbing are just a

Answer 22

Small fraction of the total number

Question 23

Substance which allow electricity to easily pass through it is

Answer 23

Conductor. The electric charges are free to move around

Question 24

Substances that offer higher resistance

Answer 24

Insulator

Question 25

A substance in between conductors and insulators

Answer 25

Semiconductors

Question 26

In conductors:

Answer 26

Charge is easily distributed

Question 27

In insulators:

Answer 27

Charges remain in the same place

Question 28

Charging can be done by....

Answer 28

Contact

Question 29

Charging by induction occurs......

Answer 29

Instantly

Question 30

There is no loss of charges during the process of .....

Answer 30

Charge by induction

Question 31

How are light objects attracted?

Answer 31

By the process of of charge by induction

Question 32

The centres of the opposite charges are found to be separated, but due to induction.....

Answer 32

The force of attraction overcomes the force of repulsion

Question 33

How do we consider the charges?

Answer 33

As point charges which are concentrated

Question 34

Additivity of a charge

Answer 34

The charge is: -Scalar(magnitude, can be added) - it can be positive or negative

Question 35

Charge is conserved

Answer 35

-in an isolated system net charge can neither be created nor destroyed - in the process the charge carrying particles can be destroyed - redistribution happens to maintain the charge

Question 36

Quantization of charge is

Answer 36

q=ne

Question 37

What is the unit of charge ?

Answer 37

Coulomb(C)

Question 38

e=

Answer 38

1.6×10^-19C

Question 39

For 1 C=

Answer 39

6.25×10^18 electrons

Question 40

At the the macroscopic level

Answer 40

Quantization of charge is observed as a stream