- #1

Coderhk

- 59

- 2

## Homework Statement

In the picture 20.40, what is the direction of the current induced in the resistor at the instant the switch is closed.[/B]

## Homework Equations

Right hand rules- Point thumb in direction of current and your fingers will curl in direction of magnetic field.

Lenz's law. The induced current always opposes the change in magnetic flux.

## The Attempt at a Solution

When the switch is closed the current will flow counter clockwise.Which implies the left side of the solenoid is north and the right side is south. Hence the magnetic field lines go from left to right. Here I assume that the magnetic field lines generated by the solenoids intersect the resistor. If the lines go from left to right, by Lenz's law the induced current must generate a magnetic field from right to left. Using the right hand rule, I get that the result is from right to left. The answer in the book is left to right.