Homework Help: Induced current by B field

1. Oct 17, 2009

deerhunt713

A region of space d = 35 cm wide is filled with a uniform magnetic field B = 2.3 T oriented normal to the plane of the screen and pointed into the screen. There is no magnetic field to the left or to the right of this region. An external agent drags a rectangular conducting loop with dimensions h = 80 cm, w = 60 cm in the plane of the screen from the left of the B field filled region (position 1 shown at left) to the right of that region (position 5 shown below) at a constant velocity of 1.2 m/s. The long side of the rectangle is always parallel to the sides of the B field filled region.

https://online-s.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys212/fall09/hwb/08/03/fig01b.gif [Broken]

https://online-s.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys212/fall09/hwb/08/03/fig01a.gif [Broken]

1) At the instant that the right side of the loop passes the center of the B field filled region (position 2 above), the induced current in the loop is

clockwise.
counterclockwise.
zero.
2) At the instant that the center of the loop passes the center of the B field filled region (position 3), the induced current in the loop is

clockwise.
counterclockwise.
zero.
3) After the loop has passed completely through the B field filled region and has reached position 5, the induced current in the loop is

clockwise.
counterclockwise.
zero.
4) At position 4 (the instant at which the left side of the loop passes the center of the B field filled region), the external agent is exerting a force of 2.7 N to the right to balance the magnetic braking force and keep the loop moving at the constant 1.2 m/s velocity. What must the current in the loop be at that instant?

0.67 A
0.87 A
1.07 A
1.27 A
1.47 A
5) What net work is done by the external agent to compensate for magnetic braking in moving the loop at the 1.2 m/s constant speed from postion 1 to position 5?

1.04 J
1.89 J
10.6 J
14.4 J
16.1 J

i have
b
c
a
c
a