I don't understand this question.

[SomethingWrong]

So I'm reading the book on physics in the chapter: Inductance.

The questions is: The long Solenoid turns/cm and carries a i = 1.5 A, its diameter D is 3.2cm. At its centre we place a 130- turn closely packed coil C of diameter d = 2.1cm. etc etc

My question is, in the solution the N is 130, but its 220.

And I noticed 2 N's. N and n. N is number of turns which should be 220 but its actually 130, and n is 220.

Shouldn't it be N1 and N2? Easier to understand, I completely skimmed it through and didn't see the lower case n.

 

[sophiecentaur]

Your question is incomplete, I'm afraid. What formula are you using and what is the value of the "The long Solenoid turns/cm" ? Show us the whole thing.

 

[jedishrfu]

Its hard to say. We would need to see the full description of the question and/or the book from which it came.

Notationally, authors are free to use whatever follows the general convention which means sometimes capitals are used for one set of parameters and lowercase for another.