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nawand

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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