Post on 23-Dec-2015
21.2 ElectromagnetismAssessment Questions 1-4
Magnetic reviewhttp://
www.youtube.com/watch?v=uj0DFDfQajw&NR=1&feature=fvwp
1. Besides a magnet what can produce a magnetic field?A moving electric charge can create a
magnetic field = electricity flowing through a wire. LT#2
We use moving magnets to generate an electric current & we use electric current to make magnets.
http://www.youtube.com/watch?v=9Zy0VHBXxLU&annotation_id=annotation_397286&feature=iv
2. How is the magnetic field of an electromagnet controlled?It can be turned on and off LT#2http://
www.youtube.com/watch?v=UBiKruVV3a0It’s strength and direction can be controlled
by controlling the current.http://www.ehow.co.uk/video_4951982_do-ele
ctromagnets-work_.html
3. How are solenoids and electromagnets used in galvanometers, electric motors and loudspeakers?They all change electrical energy into
mechanical energy. LT#1http://
www.youtube.com/watch?v=e5434dDB-7whttp://
www.youtube.com/watch?v=it_Z7NdKgmY&feature=PlayList&p=305357ACC216006C&playnext_from=PL
Galvanometers detect electric current A magnet and a wire coil are used to
measure a magnetic field caused by current.
Moving a magnet through the coil will deflect the galvanometer = generator effect. LT#3
4. How does a ferromagnetic rod inside a solenoid affect the strength of an electromagnet? LT#2
The rod makes the magnetic field much stronger.
When current flows through the coil, it creates a magnetic field that magnetizes the ferromagnetic rod.