We often experience the power of
nature. One of the most fearsome natural phenomena is
lightning. Some people might be curious why and how
it occurs. Today, we know that lightning is a flow of
electricity. In this chapter we are going to study
about characteristics of electricity.
Net Electrical Charge
Conductors and Insulators
Method of Charging
Unit of Charge: The Coulomb
When atoms gain or lose
electrons, they are called "ions."
are materials which allow very little electrical
charges and heat energy to flow. Plastics, glass, dry
air and wood are examples of insulators.
materials which electrical charges and heat energy
can be transmitted very easily. Almost all metals
such as gold, silver, copper, iron, and lead are good
materials which allow the electrical charges to flow
better than insulators, but less than conductors.
Examples are silicon and germanium.
one of these is a conductor?
(a) dry air (b) lead
(c) silicon (d) glass
(e.g. "a" )
many electrons are there in 1 C of
F is the force between the two particles,
q1 is the net charge on particle A,
q2 is the net charge on particle B,
d is the distance between the particles,
k is a proportionality constant which is 9.0 * 109
The direction of the force is on the line from one
particle to the other.
Object X has a
positive charge of 5.0 * 10-6 C.
Object Y, carrying a positive charge of 2.5 *
10-6 C, is 0.03 m away.
A. Calculate the force on X.
(e.g. "+1.55*10^10 N", or
B. What would the force be if the charge
on Y were negative.
An object, A, with
+8.25 * 10-6 C charge, has two
other charges nearby. Object B, -3.5 * 10-6
C, is 0.030 m to the right. Object C, +2.50 *
10-6 C, is 0.050 m below. What is
the net force and the angle on A?
(e.g. "1.0*10^10 N, 10 deg.")
The electric force is vector quantity. Try
to solve the problem graphically.
Try Chapter 11 Quiz and see how much
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