# Shared Flashcard Set

SCI Chapter 7
Magnets
27
Science
11/02/2010

## Additional Science Flashcards

Term
 Be able to compare and contrast: loudspeaker and microphonegenerator and motorpermanent magnets and electromagnets
Definition
Term
 How could you labeled some unmarked bar magnets if you only had one bar magnet with a north and south pole marked?
Definition
 If a side attracts to the marked north side, it must be south on the other magnet. If it repels the marked north side, it must also be north. [answer can use marked south side as well]
Term
 T or F: A compass needle uses an electromagnet.
Definition
 False, a compass needle is a thin magnet
Term
 T or F: All metals are magnetic.
Definition
 False, most metals are magnetic
Term
 T or F: An electromagnet gets weaker if you wrap wire around the core more times.
Definition
 false, the electromagnet gets stronger if you wrap wire around the core more times
Term
 T or F: Earth has two north poles and two south poles.
Definition
 true, they are called the geographic and magnetic poles
Term
 T or F: Energy that can be sent long distances to a location is called general current.
Definition
 False, energy that can be sent long distance is alternating current
Term
 T or F: Magnetic force gets weaker as you move objects away from each other.
Definition
 true
Term
 T or F: The Earth is a giant magnet.
Definition
 True
Term
 T or F: The poles of a magnet have strongest attraction when they are alike and close together.
Definition
 False, the poles are strongest when they are unlike and close together
Term
 T or F: You can increase the strength of an electromagnet by adding more current and less turns of wire.
Definition
 False, you can increase strength by adding more current and more turns of wire
Term
 What are some things that could cause a loudspeaker to stop working? How could it be fixed?
Definition
 Not plugged in - plug it in.Diaphragm is cracked - replace it.A wire is broken - replace it.
Term
 Which 3 of these do not contain electromagnets? [generators, speakers, magnetic fields, motors, and compasses, iron cores]
Definition
 Magnetic fields, compasses, and iron cores do not contain electromagnets.
Term
 alternating current
Definition
 flows in one direction and then flows in the opposite direction
Term
 compass
Definition
 instrument or tool that uses Earth's magnetic field to help people find DIRECTIONS
Term
 diaphragm
Definition
 part of the loudspeaker that VIBRATES to create sound
Term
 direct current
Definition
 current that flows in one direction
Term
 electromagnet
Definition
 COIL of wire wrapped around an iron core
Term
 generator
Definition
 device that changes motion INTO ELECTRICAL ENERGY
Term
 loudspeaker
Definition
 device that changes electrical energy INTO SOUND
Term
 magnet
Definition
 any OBJECT with magnetic force
Term
 magnetic field
Definition
 the AREA of magnetic force around a magnet
Term
 microphone
Definition
 device that changes sound INTO ELECTRICAL SIGNALS
Term
 motor
Definition
 device that changes electrical energy INTO MECHANICAL ENERGY
Term
 poles
Definition
 PARTS of a magnet where the magnetic force is strongest
Term
 shaft
Definition
 ROD that can spin and move
Term
 temporary
Definition
 lasting for only a short period of time
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