physics 121: electricity & magnetism – lecture 9 carsten denker njit physics department center...
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Physics 121: Electricity & Magnetism – Lecture 9
Carsten Denker
NJIT Physics DepartmentCenter for Solar–Terrestrial
Research
March 21, 2007 Center for Solar-Terrestrial Research
Magnetic FieldsThe force acting on a charged particle moving with velocity through a magnetic field is always perpendicular to and .Opposite magnetic poles attract each other, and like magnetic poles repel each other.
BF
v
v
BB
sinBF q v B
BF qv B
March 21, 2007 Center for Solar-Terrestrial Research
Crossed Fields
Discovery of the electron: cathode ray tube
Hall effect
Both an electric field and a magnetic field can produce a force on a charged particle.
E
B
March 21, 2007 Center for Solar-Terrestrial Research
A Circulating Charged Particle
2mvqvB
r
March 21, 2007 Center for Solar-Terrestrial Research
Magnetic Force on a Current–Carrying Wire
BF iL B
March 21, 2007 Center for Solar-Terrestrial Research
Torque on a Current Loop