Finding the Magnetic Flux of a Coil

[nokia8650]

See attached problem:

http://img72.imageshack.us/img72/4791/65321158jp4.th.jpg

The answer is 6.9 × 10−4 Wb - by multiplying the Area by the magentic flux density. Mq is, why does one not multiply this by 850 (number of turns) in order to find the answer.

Thanks

 

[sai_2008]

The flux that is coupled to the coil in dependent only on the area of the coil and the strength of the magnetic field that it is exposed to. In this case since it is oriented perpendicular to the field, all the area of the coil is exposed to the field.

It does not matter how many turns are there; the area of the coil as it "looks at the field" is still the same! Not 850, even if you had 8500000000... turns, the amount of flux cutting thru the coil is still 6.9e-4 Wb only :D

 

[thomate1]

for sharing this problem. It seems that you are trying to calculate the magnetic flux of a coil using the formula B = μNIA, where B is the magnetic flux, μ is the permeability of the material, N is the number of turns, I is the current, and A is the cross-sectional area of the coil.

In this case, since the problem does not provide values for the current or the permeability, we can assume that they are constant and do not need to be included in the calculation. Therefore, we can simply multiply the area (0.0002 m^2) by the magnetic flux density (3.45 T) to find the magnetic flux of the coil.

The reason we do not need to multiply by the number of turns (850) is because the number of turns is already included in the formula for magnetic flux. The N in the formula represents the number of turns, so there is no need to multiply it again.

I hope this helps clarify the solution for you. Keep up the good work in your scientific studies!