What is Electric Charge

It is the basic property of matter

It causes attraction and repulsion in matter in presence of other matter

The amount of electricity contained in an object is called Electric Charge

It is denoted by Q.

 

What are Different Types of Charges

There are 2 types Of Charges

  • Positive Charge
  • Negative Charge

 

Important Property of Electric Charge

There are 2 important properties of Electric Charge

Unlike Charges Attract Each Other

So Positive Charge Attracts Negative Charge

 

Like Charges Repel Each other

(2 Positive Charges Repel each other  or 2 Negative Charges Attract Each Other)

Laws of attraction and repulsion - Teachoo.png

 

What is Charge on Different Parts of Atom

We know that Atom is made up of Protons, Neutrons and Electrons

Parts Of Atom Charge
Protons They have Positive Charge
Electrons They have Negative Charge
Neutrons They have no Charge

No charge In the green balls in the image showing laws of attraction and repulsion

Note- 

If an item has equal number of Protons and Electrons, they would cancel each other, and the item would have no Charge

If it has More Protons than Electrons, it is Positively Charged

If  is has More Electrons than Protons, it is Negatively Charged

 

What is Electric Current

It is the flow of Electric Charges in Conductor

It is the amount of Electric Charge flowing in a body in 1 Second

It is denoted by I.

 

Formula for Electric Current

Electric Current = Electric Charge/Time

I = Q/t

 

What is SI unit of Electric Current

It is measured in Ampere. It is denoted by A.

As

Electric Current = Electric Charge/Time

So

1 Ampere = 1 Coulomb/1 Second

 

What are Different Units of Electric Current?

It is measured in Ampere, Milliampere and Microampere

 

Ampere

It is the SI Unit of Electric Current

It is named after French Scientist Andre Marie Ampere

As Electric current = Electric Charge/Time

So 1 Ampere = 1 Coulomb/1 Second

One ampere is defined as the current produced when a charge of 1 coulomb flows for 1 second.

 

Milliampere

It is smaller unit of Electric Current

1000 Milli Ampere = 1 Ampere

1 Milliampere = 1/1000 Ampere

1 Milliampere = 10 -3 Ampere

1 mA = 10 -3 A

 

Microampere

It is even smaller unit of Electric Current

10,00,000 Miliampere = 1 Ampere

1 Milliampere = 1/1000000 Ampere

1 Microampere = 10 -6 Ampere

1 μA = 10 -6 A

 

Electric Current is flow of electrons(negatively charged particles)

Electric Current moves from negative Side of battery to positive Side of battery

 

How does Electric Current Flow in a Circuit Diagram

In Circuit Diagram, it is represented that

Electric Current flows From Positive end to negative end

This is because when electricity was first discovered, the existence of electrons was not known

However, in reality, it is the opposite.

Electric Current flows from Negative end of battery to positive end

 

How is Electric Current Measured?

it is measured with the help of Ammeter

This instrument is connected in a series in an electric circuit

In circuit diagram, it is denoted by

Electric Current Measured by Ammeter.jpg

Questions

Q2 Page 200 - Define the unit of current.

View Answer

 

Q3 Page 200 - Calculate the number of electrons constituting one coulomb of charge.

View Answer

 

Example 12.1 - A current of 0.5 A is drawn by a filament of an electric bulb for 10 minutes. Find the amount of electric charge that flows through circuit.

View Answer

 

Question - A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly

(a) 10 20

(b) 10 16

(c) 10 18

(d) 10 23

View Answer

 

  1. Class 10
  2. Chapter 12 Class 10 - Electricity

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.