Electricity and Magnetism question

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To calculate the magnetic flux through the circular cross-sectional area of a solenoid, the magnetic field can be determined using the formula B = μ₀NI/L, where μ₀ is the permeability of free space, N is the number of turns, I is the current, and L is the length of the solenoid. The total magnetic flux linked with the solenoid is given by the equation φ = NAB, where A is the area of the cross-section. However, if the question specifically asks for the flux through a single turn, the total flux should be divided by the number of turns (N). It's important to note that the formula for B is applicable only for long solenoids, which the given dimensions suggest is valid in this case. The discussion clarifies the distinction between total flux and flux through a single turn, emphasizing the need for accurate interpretation of the problem.
matt85
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A solenoid 2.9 cm in diameter and 15 cm in length has 300 turns and carries a current of 5 A. Calculate the magnetic flux through the circular cross-sectional area of the solenoid.


-->> I tried using the equation B = u(0)NI/L to calculate magnetic field, and then putting this in the formula flux = BNA, where N is number of turns, and A is area (pi*r squared). This didn't work, though.

I'd appreciate some help! Thanks!
 
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The field is indeed given by
B=\frac{\mu_{0}NI}{L}

and the total flux through the solenoid
\phi=NAB is also right.

Maybe what they asked for is the flux through a single turn which would be your answer divided by N

Also keep in mind that
B=\frac{\mu_{0}NI}{L}
is valid only for a long solenoid. (When its length is large compared to its radius)

I feel your solenoid is long enough. I don;t see why you're not arriving at the answer.
 
yep, it was wanting it through one turn. thanks.
 
matt85 said:
... Calculate the magnetic flux through the circular cross-sectional area of the solenoid...


I think NBA is the total flux linked with the solenoid, not the flux through the cross-section. It is BA only.


MP
 

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