Transcript Electricity and Energy Resources

Ch. 7, 8, 9
ELECTRICITY AND ENERGY
RESOURCES
Ch. 7 Electricity
Electricity
Electric
Electric
Current
Charge
Positive
and
Negatives
Conductors
and
Insulators
Lightning
Circuits,
Batteries,
Ohm’s Law
(I = V/R)
Electric
Energy
Ch. 7 Electricity
Electricity
Electric
Charge
Positive and
Negatives
Conductors
and
Insulators
Lightning
Ch. 7 Electricity
Bellringer
 WRITE the question. USE your book.
 What kind of charged particle is attracted to a
positive charge?
 What is electric current made of?
 Define:
 Voltage
 Resistance
 Insulators
Ch. 7 Electricity
Electricity
Electric Current
Circuits, Batteries,
Ohm’s Law (I = V/R)
Voltage Difference is the
force that causes electric
charges to flow
Ch. 7 Electricity
Electricity
Electric Current
Circuits, Batteries,
Ohm’s Law (I = V/R)
Ch. 7 Electricity
Electricity
Ohm’s Law [I = V/R]
Current
Resistance
Electrical Power
[Power (watts) = IV])
A flow of negatively
charged electrons in
one direction
Opposes the flow of
electrons resulting in
thermal energy and
light
Electrical Energy [E
(kWh) = Pt]
Measured in Ohms
Measured in Ohms
Follows a circuit
(closed path)
Parallel or Series
Circuits
Ch. 7 Electricity
Electricity
Ohm’s Law [I = V/R]
Current
Resistance
Electrical Power
[Power (watts) = IV])
A flow of negatively
charged electrons in
one direction
Opposes the flow of
electrons resulting in
thermal energy and
light
Electrical Energy [E
(kWh) = Pt]
Measured in Ohms
Measured in Ohms
Ch. 7 Electricity
Electricity
Ohm’s Law [I = V/R]
Electrical Power
[Power (watts) = IV])
Electrical Energy [E
(kWh) = Pt]
Current
A flow of negatively
charged electrons in
one direction
Measured in Amps
Follows a circuit
(closed path)
Parallel or Series
Circuits
Resistance
Static Electricity
Voltage
Build up of excess
charges on an object
Opposes the flow of
electrons resulting in
thermal energy and
light
The force that causes
electrons to flow
A sudden discharge
of negatively charged
electrons
Measured in Ohms
Measured in Volts
Lightning
Problems to Solve
1. Calculate the voltage difference in a circuit
with 25 ohms resistance if the current is 0.5
amps.
2. A current of 5 amps flows in a 600 watt light
bulb. The voltage difference between the
filament ends is 120V. What is the resistance
of the filament?
Problems to Solve
3. What kind of a circuit is this?
Problems to Solve
2. What kind of a circuit is this?
Problems to Solve
5. A toaster is plugged into an outlet where the
voltage is 120V. How much power does it
use if the current is 10A?
6. A VCR on powersave mode (not on) still uses
10 W of power. What is the current if the VCR
is plugged into 220 V?
7. A flashlight bulb uses 2.4 W of power when
the current in the bulb is .8 A What is the
voltage difference supplied by the battery?
Problems to Solve
8. A microwave with a power rating of 1,200 W
is used for .25 h. How much electrical energy
is used by the microwave?
9. A refrigerator operates for about 18 hours a
day. The 700 W rating on a fridge means it
uses ________ of electrical energy each day.
Ch. 8 Magnetism
Magnetic Poles
Ch. 8 Magnetism
Ch. 8 Magnetism
Ch. 8 Magnetism
 The magnetic flux lines up the compass
arrows along their North-South orientation
Ch. 8 Magnetism
Ch. 8 Magnetism
 What happens when the current is reversed?
Ch. 8 Magnetism
 Electric Motors
Ch. 8 Magnetism
 Electric Motors
Ch. 8 Magnetism
 When electric current travels through a wire a
magnetic field forms. Notice the change in
direction. Why?
Ch. 8 Magnetism
 When electric current travels through a wire a
magnetic field forms. By forming many loops
why is the magnetic field increased?
Ch. 8 Magnetism
 When electric current travels through a wire a
magnetic field forms. By forming many loops
why is the magnetic field increased?
 http://science.howstuffworks.com/electroma
gnet2.htm
Ch. 8 Magnetism
 Successfully write and answer #1-13 p. 218 &
#1-14, p. 250
In groups describe how an electrical
generator works. Video answers.
Ch. 8 Magnetism
 Remember the “Right Hand Rule” to
determine the direction of the magnetic flux
caused by a current.