Motion of a Charged Particles
When the velocity of a charged particle is perpendicular to a uniform magnetic field, the particle moves in a circular path in a plane perpendicular to B
Magnetic forces do NOT do any work on moving charges
Berapa besar jari-jari lintasan r ?
Bq
mvR
R
vmqBv
FF SB
2
Applications• A charge moving with a velocity v in the presence of both an
electric field E and a magnetic field B experiences both an electric force qE and a magnetic force qv x B.
• The total force (the Lorentz force) acting on the charge is
Sources of Magnetic Field : electric current
Jean-Baptiste Biot (1774–1862) and Félix Savart (1791–1841) performed quantitative experiments on the force exerted by an electric current on a nearby magnet.
Biot–Savart law :
where μo is a constant called the permeability of free space
μo = 4π x 10-7 T∙m/A
The total magnetic field B created at some point by a current of finite size:
Contoh : Magnetic Field due to a Finite Straight Wire
Magnetic Field due to a Circular Current Loop
Ampere’s Law
Solenoid We can use Ampere’s law to calculate the magnetic field strength inside an ideal solenoid. The line integral of B along this loop is
What happens if the length of the solenoid is finite?
Toroid
TERIMA KASIH