Transcript Electricity powerpoint

ELECTRICITY: CIRCUITS
& CURRENTS
CIRCUITS VS. CURRENTS
Electrical circuit: a closed loop where charged
particles flow
 Electrical current: a flow of charged particles
(e-)
 Direct current (DC): a flow of charged particles
in one direction only
 Alternating current (AC): a flow of charged
particles in either direction (1st in one direction,
then the other)

CURRENT
The amount of electrons that pass a given point
in one second.
 Current = I
 Unit = Ampere (A)
 1 ampere = 6,250,000,000,000,000,000
(6.25 x 1018) electrons passing a point in 1
second
 1 amp = 1,000 mA

VOLTAGE
The electrical pressure or force
 Voltage = V
 Unit = volts (V)
 Sometimes referred to as electric potential
difference

RESISTANCE
The degree to which a conductor hinders the
flow of charged particles
 Resistance = R
 Unit = ohm (Ω)
 No conductor is perfect. Some current is lost
(usually to heat)

OHM’S LAW
Ohm's law = the current through a conductor
between two points is directly proportional to
the voltage across the two points.
 Formulas:
V=IxR
I=V/R
V
R=V/I

I
R
POWER
The work performed by an electrical current
 energy/time
 Power = P
 Unit = watt (W)
P
P=VxI
V
I
V=P/I
I = P/V

EXPENDED CAPACITY
How
much energy you use by the
hour
Units Watt-hour or Kilowatt-hour
EC= P × t