Definition
Static electricity is the build up of
electrical charge on an object. You
may feel this in the form of a shock
when you approach a metal object
or another person.
CONSERVATION OF CHARGE
The conservation of charge states that charge cannot
be created or destroyed, only transferred. Objects
become charged through friction, conduction, or
induction, but the total charge in a system remains
constant. For example, rubbing your feet on a carpet
transfers electrons, making you negatively charged
while the carpet becomes equally positive. This
principle ensures that any charge gained by one object
is lost by another, maintaining balance.
WAYS TO CHARGE AN OBJECT
1. Friction – Rubbing two materials together transfers electrons.
Example: Rubbing glass with silk makes the glass positive and silk
negative.
2.Conduction – Direct contact with a charged object transfers
charge. Example: A charged glass rod touching a metal object
transfers the same charge.
3.Induction – Charging without direct contact by bringing a charged
object close, causing charge redistribution.
THE ELECTROSCOPE
The electroscope is a sensitive instrument used to detect electric
charge. It consists of a glass container with a metal rod inside, to
which two thin pieces of gold foil are attached.
One end of the metal rod has a metal plate attached to it,
located outside the glass container.
When the electroscope detects an electric charge, the gold
foil pieces spread apart due to the repulsion between like
An electroscope detects electric charge by using a charged charges.
object to induce a charge in its metal parts. When a charged
rod is brought near, it causes the electroscope's gold foil to
repel because like charges push away. This happens without
direct contact, and the foil spreads apart due to the induced
charge. After the rod is removed, the electroscope returns to its
neutral state.
POLARIZATION
Polarization occurs in insulators when a charged object
causes a shift in the position of electrons within the
material's atoms. This redistribution of charges creates a
slight positive charge on one side and a negative charge on
the other, but the object remains overall neutral. This effect
can lead to the attraction of the polarized object to the
charged object, even though no charge is added or removed.