Electricity and Magnetism Unit

Travis build a circuit that would run a small motor.  Travis's circuit has changed the electrical energy into what other form of energy?

• sound
• heat

• motion

• light

Sarah plugged her CD player into the electrical socket so that she could use it to practice the song she was going to sing in chorus tomorrow.  Which statement explains why she could listen to her CD?

• The electrical energy was not changed.
• The electrical energy was changed into light energy.
• The electrical energy was changed into heat energy.
• The electrical energy was changed into sound energy.

Why are many electrical wires wrapped with a plastic coating?

• Because plastic is less expensive than steel.
• Because plastic is able to keep its shape.
• Because plastic is a good insulator.
• Because plastic is a good conductor.

Which of the following materials is the best conductor of electricity?

• glass
• copper wire
• rubber band
• piece of string

Bar magnets have two poles.  What are they?

• north and south
• red and blue
• east and west
• red and green

If magnet A can pick up 3 steel paperclips and magnet B can pick up 5 steel paperclips, which one is stronger?

• Magnet A

• Magnet B
• both are equally strong
• magnets don't attract steel paperclips

Which of the following things can you pick up with a magnet?

• a plastic straw
• a wooden pencil
• an iron nail
• a copper penny

Where is the pushing or pulling force of a magnet strongest?

• in the middle of the magnet
• at the ends of the magnet
• the force is the same all the way through the magnet
• no one knows where the force is the strongest

Gabriel used an iron bolt to build an electromagnet that will pick up 4 pins.  How can he increase the strength of his electromagnet so that it will pick up 10 pins?

• He can use fewer coils of wire around the iron bolt.
• He can use a bigger iron bolt that has a greater diameter.
• He can use a smaller battery.
• He can use a smaller iron bolt that has a smaller diameter.

Electricity is usually converted into another form of energy before it is useful to people.  What is one example of an object that converts electricity into heat?

• oven
• microphone
• motor
• lamp