Chapter 21, Problem 8P

(a)

To determine

Direction of the current induced in the small circular loop.

Answer to Problem 8P

Solution:The direction of current induced is counter clock wise.

Explanation of Solution

Given:

Figure of loops

  

Figure.1

As the resistance of the outer loop increases, the voltage will decrease and by Faraday’s law of electromagnetic induction, the magnetic flux of the outer loop will also decrease.

The change in magnetic flux will induce the current in the inner loop due to mutual induction, the flux induced in the inner loop will have the same flux as the outer loop, and the direction of the current in the inner loop will be the same as the outer loop, thus the direction of current in the inner loop is counterclockwise.

Conclusion:

The direction of the current induced is counterclockwise.

(b)

To determine

Direction of the current induced in the small circular loop if the smaller loop is placed outside the larger one

Answer to Problem 8P

Solution:The direction of the current induced is clockwise.

Explanation of Solution

Given:

Figure of loops

  

Figure.2

As the resistance of the outer loop increases, the voltage will decrease and by Faraday’s law of electromagnetic induction, the magnetic flux of the outer loop will also decrease.

The change in magnetic flux will induce the current in the smaller loop due to mutual induction.The flux induced in the smaller loop will have the opposite flux as the outer loop, and the direction of the current in the smaller loop will be opposite as the outer loop, thus the direction of current in the inner loop is clockwise.

Conclusion:

The direction of the current induced is clockwise.