Download Electric Potential

Electric Charge and Electric Fields
Coulomb’s law:
This equation gives the magnitude of
the force.
Coulomb’s Law
The force is along the line connecting the
charges, and is attractive if the charges are
opposite, and repulsive if they are the same.
Coulomb’s Law
**Unit of charge: coulomb, C**
One Coulomb….C…6.3 x 1018 elementary charges
**The Electrostatic constant in**
Coulomb’s Law is then:
Electrostatic Constant….k…..9.0 x 109 N·m2/C2
Charges produced by rubbing are
typically around a microcoulomb:
Coulomb’s Law
Charge on the electron:
1 elementary charge = -1.6 x 10-19 C
The Gravitational Field
An area in space where
force acts on a mass.
The Electric Field
An area in space where
force acts on a charge.
The Electric Field
The electric field intensity is the force on
a small charge, divided by the charge:
F
E = ------q
The Electric Field
The Electric field intensity for a
point charge:
q
E = k ——
d2
Electric Field Lines
The electric field can be represented by
field lines. These lines start on a positive
charge and end on a negative charge.
Electric Field Lines
•The number of field lines starting on a
positive charge and ending on a negative
charge is proportional to the magnitude of the
charge.
•The electric field is stronger where the field
lines are closer together.
Electric Field Lines
Two equal charges, opposite in sign:
Electric Potential
V = voltage or Electric Potential
V=
Potential Energy
------------------------Charge
Electric Potential
1V =
1 Joule
-----------------1 coulomb