The magnetic force on a charged particle 1) depends on the sign of - - PowerPoint PPT Presentation

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Mar 12, 2024 45 likes •139 views

The magnetic force on a charged particle 1) depends on the sign of the charge on the particle. 2) depends on the velocity of the particle. 3) depends on the magnetic field at the particle's instantaneous position. 4) is at right angles to both

SLIDE 1

The magnetic force on a charged particle

1) depends on the sign of the charge on the particle. 2) depends on the velocity of the particle. 3) depends on the magnetic field at the particle's instantaneous position. 4) is at right angles to both the velocity and the direction of the magnetic field. 5) is described by all of these.

SLIDE 2

Electric Force: Magnetic Force:

q  F E  

q   F v B   

SLIDE 3

Figure 27.17

SLIDE 4

Cyclotron motion

Radius of orbit
Period – time for one complete orbit.

mv R qB  2 R v T  

SLIDE 5

Velocity Selector

Figure 27.21a

SLIDE 6

Figure 27.33

Mass Spectrometer

mv r qB  

SLIDE 7

A positively charged particle moves with speed v in the positive x direction. A uniform magnetic field of magnitude B exists in the negative z direction. You want to balance the magnetic force with an electric field so that the particle will continue along a straight line. The electric field should be in the 1) positive x direction. 2) positive z direction. 3) negative y direction. 4) negative x direction. 5) negative z direction.

SLIDE 8

Currents in Magnetic Fields

Current:

– Each charge q feels a magnetic force: – Force on a wire segment of length dl is the force

n all of the charges in that segment:

I qnv A 

q   F v B    ( ) ( ) dQ qn Vol qn Adl  

( )

d d

d dQ qn Adl I       F v B v B dl B       

SLIDE 9