Download - Today4/14
Today4/14 B-Field due to many wires HW: 4/14 “Wires” Due Thursday, 4/17 Magnetism HW delayed till Monday 4/14
I will go over it today Force on Loops and Torque on loops both due
on Wednesday 4/16 Friday and Monday are holidays! Lab: e/m ratio for electron
Lab:
e-
radius of curved path
Electron gun
V
Current carrying coils (two separate coils)
Exactly like HW due today
Magnetic Forces, WiresFind the force on wire 3 caused by wire 1 and 2.
I2 I1
I3
r
r2 r
Magnetic Forces, WiresFirst find the direction of the B field at the X. All currents are the same
I2 I1
B1 = 0 I/2 r
Bnet = B1 +B2 added as vectors
B2 = B1/ 2
r
As an example, find Bnet
B2
= Bo
B2 = Bo/ 2
B1,y = 0 B1,x = Bo
B2,y = Bo/2 B2,x = Bo/2
Bnet = Bo/ 2
45
Magnetic Forces, WiresNow find the force on wire 3.
I2 I1
I3
F = I l Bnet
Bnet
Note: Sin = 1 = 90
F = IlBo/2