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Homework Statement
Use Lenz’s law to answer the following questions con-
cerning the direction of induced currents. Express
your answers in terms of the letter labels a and b in
each part of Figure P31.22. (a) What is the direction of
the induced current in the resistor R in Figure P31.22a
when the bar magnet is moved to the left? (b) What
is the direction of the current induced in the resistor
R immediately after the switch S in Figure P31.22b is
closed? (c) What is the direction of the induced cur-
rent in the resistor R when the current I in Figure
P31.22c decreases rapidly to zero?
[/B]
Find the direction of current http://www.chegg.com/homework-help/questions-and-answers/use-lenz-s-law-answer-following-questions-concerning-direction-induced-currents-express-an-q7530693
Homework Equations
F=I L x B
The Attempt at a Solution
By looking at the picture "a" we see the poles of magnet pointed to the right, so the magnet field would be to the right on the coil, this is only possible if the current would pass clockwise. Since the magnet is leaving to the the left, the flux is decreasing. The system responses by creating a magnet field that compensates its leaving so the direction of current in the coil would be clockwise. Which is opposite to the answer sheet.
By b is either not sure whether solutions are good. Whenever switch is closed the flux will be increased so the magnet field pointed to the right. The system responses by opposing these increasing. The only way to do this is to send an induced current from b to a in the resistor.
c is good!
Hope someone corrects me if there is anything wrong,
Thanks