Static electricity

2. WARM UP
Have you ever had an
electric shock when getting
out of a car?
Lightning is a form of
electricity

3. LEARNING OBJECTIVES
Students will be able
1.to recall that electric charges are
seperated when certain materials are
rubbed against one another ,that
polythene becomes negatively charged
and perspex becomes positively
charged when rubbed with cloth
2.Explain charging of objects in terms of
properties of objects which are free to
move

4. Static Electricity
Static electricity occurs when charges build up
on the surface of material.it is called static
because the charges do not move

5. Why does a balloon , charged by rubbing,
stick to the ceiling?.
The balloon on rubbing becomes
negatively charged. The negative charge on
the balloon repels some of the electrons in
the wall away from the surface. This leaves
the wall surface positively charged. Since
opposite charges attract, the balloon gets
attracted to the wall

6. CHARGING BY INDUCTION

7. FINAL ASSESSMENT
1.What do you mean by static electricity?
2. Explain how polythene becomes negatively charged
and perspex becomes positively charged when
rubbed with cloth.
3.Explain charging by friction.
4.Write the three different ways of charging.
5.Why does a balloon , charged by rubbing, stick to
the ceiling?
6.Explain charging by induction with the help of a
diagram.