I am having difficulty on a conceptual question. I am thinking mastering physics is wrong here.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

When a magnet is plunged into a coil at speed , as shown in the figure, a voltage is induced in the coil and a current flows in the circuit.

The same magnet is plunged into a coil that has twice the number of turns as before, as shown in the figure. (Part B 1 figure) If the speed of the magnet is again v, the induced current in the coil is _______ .

A - twice as much

B- four times as much

C- half as much

D - unchanged

2. Relevant equations

3. The attempt at a solution

I answered with twice as much. which coincidentally the book on page 703 (college physics 8th edition) has this same example in it with the answer twice as much. Am I missing something? What answer do you get?

Mastering Physics replied with this to my answer:

Recall that the current in the coil is proportional to the induced emf, and inversely proportional to the resistance of the coil. Since the induced emf is proportional to the number of identical turns present in the coil, the induced voltage will be greater than that in the coil with fewer turns. How will the number of turns affect the resistance of the coil? Note that the turns in the coil are in series.

Thanks

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# Magnet and a Coil - induced current

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