In the figure below a metal rod of length L moves to the right at speed v. http:
ID: 2182420 • Letter: I
Question
In the figure below a metal rod of length L moves to the right at speed v.http://www.webassign.net/grrphys2/20-figure-02-alt.gif
(a) What is the current in the rod, in terms of v, B, L, and R?
I =
(b) In what direction does the current flow?
clockwise
counter-clockwise
(c) What is the direction of the magnetic force on the rod?
up
down
left
right
out of the page
into the page
(d) What is the magnitude of the magnetic force on the rod (in terms of v, B, L, and R)?
F =
Explanation / Answer
calculate the area as function of time: A=L*v*t the flux is: f=A*B=Lvt*B change of flux in time is the emf: e=LvB the current in wire is: I=e/R=LvB/R current shall flow counterclockwize so the magbetic field produced by it will be in opposite direction to the existing field. c) the force will be F=I x B--> it will be to the left d) F=IxB=LvB^2/R