2. E3dady 2013-2014 Electricity Dr. Mona
1-10-2013
It was known to the ancient Greeks as far back as 600 B.C that
amber, rubbed with wool, acquired the property of attracting
light objects.
3. E3dady 2013-2014 Electricity Dr. Mona
1-10-2013
The modern theory of matter is based upon the principle that all
substances are up of atoms and molecules . Each
atom contains a number of negatively charged particles, called
electrons, revolving around the atomic nucleus . The
nucleus contains uncharged particles called neutrons, each
atom has equal amount of negative and positive charges which
is called the atomic number
4. E3dady 2013-2014 Electricity Dr. Mona
1-10-2013
When we rub a glass rod with silk some of the electrons leave
the glass to the silk . So the glass rod is said to be positively
charged
So we have 2 types of
charges
+ Charge
- Charge
The same charges repel
Different charges attract
5. E3dady 2013-2014 Electricity Dr. Mona
1-10-2013
The minimum electric charge is the electronic charge and
denoted by e . It has the magnitude of 1.6 * 10^ (-19) c. any
physically existing charge as integral multiple of e, which
means that charge is quantized” – “.
6. E3dady 2013-2014 Electricity Dr. Mona
1-10-2013
This force is directly proportional to the product of the two
charges q ₁ and q₂ , and inversely proportional to the square of the
separation, r, between the two charges . This force is repulsive if the
charges have the same sign, and attractive if they have opposite signs
