F) Magnetic Force on moving charges

Electron in Magnetic Field - St. Mary's H.S.

When a charge is shot through a magnetic field it experiences a force.

Moving Charges create their own magnetic field


 

To maximize charge deflection in a magnetic field ....

 

a) How would you shoot a charge through a magnetic field?

Fast or Slow??

 

 

Fast


b) What kind of charge would you use?

Big Charge or Small Charge?

 

 

Big


c) What strength magnetic field would you use?

Strong or Weak??

 

 

Strong


1. Fmag = Bqv 

 

B - flux density of magnetic field (strength)

 

q - charge (C)

 

v - velocity (m/s)


The magnetic force is maximum when the charge moving perpendicular to field


 

 

The magnetic force is 0 when the charge moving parallel to field


 

2. Finding the direction of the magnetic force on a free charge moving through a magnetic field

Electron in Magnetic Field II - St. Mary's H.S.

 

 

Use 3rd Left hand Rule

1) Draw in flux lines

 

2) Thumb - direction of moving charge

 

3) 4 fingers - direction of magnetic Field

 

4) Palm - direction of force on charge



Answer: Into or Out of the page?



Figure 2: When this charge reaches the magnetic field, where will it be pushed?

 

Into or Out of page?

 

Into Page

 

Television Tube - Physics 2000

 

Left Hand Rule Game - St. Mary's H.S.