Magnetic field due to a solenoid

  • Thread starter Jahnavi
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  • #1
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Homework Statement


solenoid.png


Homework Equations




The Attempt at a Solution



I am having trouble interpreting the language of the problem statement . What does it mean that "half number of turns are wound " ?

When the solenoid is cut , the length becomes 1/4th of the original and number of turns also become 1/4th of the original .

I think the problem is not difficult if only I could understand the question .

Thanks .
 

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Answers and Replies

  • #2
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That is a strange question. Are the four equal parts picked up again later?
If not, I don't understand that part. I would assume the density of the windings (windings per length) is halved.
 
  • #3
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Are the four equal parts picked up again later?

I think so .

I would assume the density of the windings (windings per length) is halved.

How ?

What does it mean "half number of turns wound on any one piece " ?
 
Last edited:
  • #4
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Well, the sentence does not use correct English grammar, so it is a bit speculation, but I interpreted it as "For each quarter, we halve the winding density". For the following question this means the quarters don't matter.
I think so .
Can you show the full problem with its context?
 
  • #5
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Can you show the full problem with its context?

That is all I have . This is an objective type MCQ from a test paper .

I interpreted it as "For each quarter, we halve the winding density".

This interpretation gives option 4) . Right ?

For the following question this means the quarters don't matter.

Could you explain this .
 
  • #6
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This interpretation gives option 4) . Right ?
Sure.
Could you explain this .
You didn't use the part about quarters to arrive at the answer of B/2, right?
 
  • #7
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Option 2) is the answer given .Please see the solution .

Solution3.png


I think what they ( paper setters ) are trying to do is halving the total number of turns (before the solenoid is cut ) and then fitting those N/2 turns in the length L/4 ( after the solenoid is cut in four ) . Strange interpretation :wideeyed: .

Please let me know if the official solution makes sense to you .
 

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  • #8
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I can see how you could interpret the problem that way, but the phrasing is unnecessarily complicated and ambiguous.
 
  • #9
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Thanks !
 

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