Unformatted text preview: s a current of
0.25 Amps. The wires are wrapped around a core with a relative permeability of 60.
What percentage of the magnetic field within the core of the toroid is produced by atomic
currents?
A) 37%
B) 98%
C) 63%
D) 1.3%
E) 0% Version 1 Page 3 7. Two of Maxwell's equations contain a path integral on the left side and an area integral
on the right. These equations require that:
A) the area must be wellseparated from the path
B) the path must be along a field line and the area must be perpendicular to the field line
C) the area must be flat and contain the path
See figure 29.21 (page 975) for a diagram
D) the path must pierce through the area
illustrating a path around the boundary of a
E) the path must be the boundary of the area
nonflat surface. Also, recall the giant
"windsock" demo. 8. Find the magnitude and direction of the magnetic field produced at point P by the current
element shown in the diagram. The lengths in the diagram are x1=40 cm and z1=30 cm.
The current is 5 amps and the current element is 1 cm long. (Note that in the coordinate
system pictured in the diagram the y axis points into the page). A)
B)
C)
D)
E) 5.3 x 105 T in negative z direction
3.4 x 107 T in negative y direction
9.1 x 108 T in negative x direction
0 Tesla
1.2 x 108 T in negative y direction Version 1 Page 4 9. The resistance R in the rail gun pictured below is initially 100 Ohms. Consider what
happens to the terminal velocity vt and the initial acceleration a0 at time t=0 if we replace
this resistor with one that is 200 Ohms. (t=0 is t...
View
Full Document
 Fall '08
 DaveWinn
 Physics, Magnetic Field

Click to edit the document details