Cracking the SAT Physics Subject Test

(Marvins-Underground-K-12) #1

Summary


When a particle with a charge (q) moves through a magnetic field (B), it
experiences a magnetic force (FB). The direction of FB is perpendicular to
both v and B and is given by the right-hand rule.

Magnetic forces affect moving charges, and a current-carrying wire contains
charges that move. The magnetic force that affects a wire that carries a current
is represented by the equation FB = IℓB sin θ.

Magnetic forces never change the speed of a charge, they only turn it.

Magnetic forces do no work.

Magnetic fields are created by current-carrying wires because of the motion of
the electric charges that flow down a wire. The current (I) generates a
magnetic field (B) in the surrounding space that is proportional to the current
and inversely proportional to the distance from the wire (r). Use the equation

B∝.

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