Download - Electromagnetic Induction
Electromagnetic Induction
https://www.youtube.com/watch?v=9gsARla8h9w
https://www.youtube.com/watch?v=AiYnDskFxTo
https://www.youtube.com/watch?v=J4L33M4-CAI
Prototype for the railgun to launch objects into outer space at 3 km/sec.
..\..\PP movies\physics videos\Demonstration_of_the_Navy_Electromagnetic_Rail_Gun_prototype.flv
..\..\PP movies\physics videos\MIT Physics Demo -- Inductor Radio.flv
..\..\PP movies\physics videos\Watch_This_1_25_Kilojoule_DIY_Coilgun_Smash_Various_Househol.flv
http://www.fool.com/investing/general/2015/02/08/navys-new-mach-7-cannon-could-be-a-game-changer.aspx#.VNeVwSpqB3s.email
Why does this happen?
Induction• Recall: potential difference (measured in
Volts) caused current to flow• It is also possible to induce (cause) a
current (and V) with a changing magnetic field (B)
• Relative motion between part of a circuit and a magnet is one way to induce current
Induction• Voltage, referred to as emf (electro-
motive force) often in this chapter, is also induced
• Recall: emf is defined as energy per unit charge supplied by a source of current.
• Direction of current depends on direction of B and the relative motion of the magnet & circuit (right hand rule).
Ways to induce current
1. Move circuit in/out of magnetic field, or move magnetic field across circuit
2. Rotate circuit in a constant magnetic field
3. Vary the magnetic field while the circuit is in it
• An induced current also makes its own magnetic field. The resulting induced B is always in opposition to the changing original (source) field