Download ELECTRICAL POTENTIAL ENERGY


ability to move an electric charge from one
point to another.

EPE of moving charge decreases because
electric field does work on charge.

depends on distance between two charged
objects

work that must be done against electric forces
to move a unit charge from one point to the
other.

measured in volts, V
VOLT

equivalent to one joule per coulomb (1 J/C).

aka voltage.

device that is a source of electric current
because of a potential difference (voltage)
b/w terminals.

Positive & negative.

Batteries convert chemical energy into
electrical energy.
Measure of energy available to move
electrons.
 Electrical potential difference b/w two
points.
 sets charges in motion.

rate that electric charges move
through a conductor.
SI unit:
 ampere, A.
 1 amp = 1 C/s

 electrons flow in same direction in a
wire.
 electrons flow in different directions
in a wire
Resistance:
 opposition posed by a material or a device to the
flow of current.
 caused by internal friction
 which slows the movement of charges through a
conducting material.
SI unit:
 ohm, Ω.
 1 Ω = 1 V/A
Resistor:
 special type of conductor used to control current.
Resistance =
voltage/current
 V: potential difference
(V)
 I: current (A)
 R: resistance

V
R
I
A light bulb with a resistance of 160 Ω is
plugged into a 120 V outlet. What is the
current flowing through the bulb?
GIVEN:
WORK:
R = 160 
V = 120 V
I=?
V
I=V÷R
I = (120 V) ÷ (160 )
I = 0.75 A
I R
Ohms
4
15
2
9
6
Volts
100
150
30
45
48
Amps
25
10
15
5
8
Superconductors
 Certain metals & compounds have zero
resistance when their temperature falls
below a certain temperature (critical
temperature).
Semiconductors
 intermediate to conductors and
insulators.
Material of wire
 aluminum and copper have low resistance
Thickness
 Thicker wire lower resistance
 Thinner wire higher resistance
Length
 shorter wire lower resistance
 Longer wire higher resistance
Temperature
 lower temperature lower resistance
 Higher temperature higher resistance