Download Heat, Electricity, and Magnetism Study Guide

Name: __________________ Teacher: __________________ Test Date: __________
4th Grade Heat, Electricity & Magnetism
Study Guide
Vocabulary:
1. Increase – To become or make greater in size or amount
2. Decrease – To become or make less in size or amount
3. Heat – The transfer of thermal energy from one object to another. Heat always moves from warmer objects to
cooler objects.
4. Temperature – The measurement of the average energy of particles in an object.
5. Celsius – Most scientists use this scale to measure temperature. Freezing point = 0:C, room temperature =21:C,
body temperature = 37:C, Boiling Point = 100:C
6. Fahrenheit – This measurement of temperature is mainly used in America. Freezing point = 32:F, room
temperature = 70:F, body temperature 98.6:F, boiling point 212:F.
7. Current Electricity – The flow of electrical charges through a circuit.
8. Simple Circuit – The path along which electric current flows.
9. Open Circuit – A circuit with gaps, so that it is not complete, and therefore, electricity will not flow through it.
10. Closed Circuit – A complete, unbroken circuit to allow electricity to flow through it.
11. Power Source – An object to power the electric current, such as a battery.
12. Energy Transfer – When energy flows from one object to another.
13. Conductor – Objects that transfer heat and electricity very well.
14. Insulator – Objects that do not transfer heat very well.
15. Compass – A tool that uses Earth’s magnetic field to show direction. The needle of a compass is a thin needle
that will point to a magnetic field (usually the Earth’s).
16. Magnet – An object that attracts to iron, nickel, and cobalt.
17. Magnetic Field – The area of magnetic force around a magnet. Every magnet has a magnetic field that wraps
around it.
18. Magnetic Poles – The force of the magnet is strongest at the pole. A magnet has two poles, a north end and a
south end.
19. Attract – Two magnets pull toward each other.
20. Repel – Two magnets push away from each other.
Heat
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Heat moves from one object to another- we call this heat transfer
Heat always moves from warmer to cooler objects
As the energy increases, the heat increases
As the energy decreases, the heat decreases
Heat energy is produced by:
o friction
o electricity flowing through a circuit
o burning
Temperature is the measurement of the average energy in an object
Heating can change an object’s temperature
Insulators of heat do NOT transfer heat very easily they keep the heat IN
o Wool, fur, and blubber are examples of insulators of heat
Conductors of heat DO transfer heat very easily and quickly.
o Metal and water are great conductors of heat
Electricity
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Electrical energy is transferred (or moved) through a circuit.
o A circuit is the path that the electricity flows.
o For our studies, we focused on simple circuits.
o Closed circuit: A complete, unbroken circuit to allow electricity to flow through it.
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 The electrical energy is changed into light & heat energy through the lamp.
Open circuit: A circuit with gaps, so that it is not complete, and therefore, electricity will not flow through
it.
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 This circuit is open; the electricity cannot flow through it so the light does not turn on.
When you connect the ends of a wire to the terminals (or ends) of a battery, what happens? What have
you created? You have created a closed circuit and energy will flow through.
o
Just like heat, electricity has conductors and insulators, too!
 Good conductors of electricity: Metals, water
 Good insulators (poor conductors) of electricity: plastic, wood, rubber, fabrics
Magnets
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An object that attracts to iron, nickel, and cobalt.
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Magnets always have 2 poles; north & south
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Opposite poles attract each other (N-S)
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Like poles repel each other (N-N & S-S)
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Magnets have a magnetic field, or invisible lines of force.
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This can be demonstrated using iron fillings:
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The iron filings show these invisible lines of force.
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Magnetic fields are all around a magnet.
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In the above picture, you can see that the iron filings go all around the magnet.
All magnets do not have the same strength.
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The stronger a magnet, the more magnetic objects can be attracted to the magnet.
o
Strength is determined by:
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Size (only sometimes- small magnets can be very powerful!)
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Shape
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Weight
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Kind
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Distance from the object
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The closer an object is to a magnet the stronger the attraction.
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The farther a magnetic object is from a magnet the weaker the attraction.
Closed circuits possess magnetic properties
o
If we put a compass near a closed circuit the needles of each compass pointed toward the circuit
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What happened when we opened the circuit?
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The needles of each compass pointed in the original direction again
What happened when you moved the compasses farther away from the circuit?
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The farther away the compass was from the circuit, the less likely it was to point toward
the circuit.
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Why is this so? What creates the magnetism?
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The flow of the electricity through the wire!
We can create an electromagnet by using this concept
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In class, we wrapped wire around a nail and attached the ends of the wire to the terminals, or
ends, of a battery.
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When we create a closed circuit, we are allowing the electricity to flow through the wire. The
electricity is made up of several charged particles, called electrons. This movement is called an
electrical current.
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This electrical current acts like a magnet (compass activity)
Sample questions:
1. Which of the following are forms of energy?
a. Heat
b. Electricity
c. Both a & b
d. None of the above
2. Which of the following are examples of producing heat energy?
a. Rubbing your hands together
b. an electric curling iron
c. lighting a candle
d. all of the above
3. Which of the following would be good conductors of heat?
a. Iron skillet
b. Blubber
c. Cotton sweater
d. Wool socks
4. Which of the following would be good insulators (poor conductors) of electricity?
a. An aluminum pan
b. Cotton ball
c. A magnet
d. Water
5. What is this diagram showing?
a. An open circuit
b. A closed circuit
c. A light bulb circuit
d. An electromagnet
6. In a simple circuit above, what would happen if the left wire touched the battery?
a. It would turn on the light, creating an open circuit
b. It would turn off the light, creating a closed circuit
c. It would turn on the light, creating a closed circuit
d. Nothing will happen
7. What is demonstrated when iron filings are sprinkled around a magnet?
a. the strength of magnets
b. the shape of the magnetic field
c. the distance of magnets
d. none of the above
8. The weaker the magnet, ___________________.
a. the fewer magnetic items are picked up
b. the more magnetic items are picked up
c. the fewer non-magnetic items are picked up
d. the more non-magnetic items are picked up
In the following diagram, demonstrate the effects of a simple electric circuit on a compass by selecting the direction
the needle is pointing at that location.
9.
a. north
b. south
c. east
d. west
10. The diagram in question 9 proves that the electricity that flows through a simple circuit ___________.
a. is really cool
b. creates a magnetic field
c. does not create a magnetic field
KEY: 1) c 2) d 3) a 4) b 5) a 6) c 7) b 8) a 9) c 10) b