Mutual Inductance of the cylinder coils

[Romperstomper]

Two coils are wrapped around the same cylinder form. When the current in the first coil is decreasing at a rate of -.242A/s, the induced emf in the second coil has a magnitude of .00165 Volts. What is the mutual inductance?

What I did:

E_2 = -M(\frac{d_i_1}{d_t})

.00165/-.242 = -M

.006818H.

The answer given is 1.96H. I went over it several times and I keep coming back to this equation. Am I wrong, or is the book wrong?

 

[Nylex]

I assume the book's wrong, your working looks fine to me.

 

[wais]

Based on the given values and the equation you used, it seems like your calculation is correct. However, it is always a good idea to double check your work and make sure you are using the correct units and conversions. It is also possible that the answer given in the book is incorrect. You may want to consult with a classmate or your instructor to see if they can confirm the correct answer.