Neurons in our bodies carry weak currents that produce detectable magnetic field

Question

Neurons in our bodies carry weak currents that produce
detectable magnetic fields. A technique called magnetoencephalography, or MEG,
is used to study electrical activity in the brain using this concept. This technique
is capable of detecting magnetic fields as weak as 1.0 x 10^-15 T. Model the neuron
as a long wire carrying a current and find the current it must carry to produce
a field of this magnitude at a distance of 4.0 cm from the neuron.

Provide full explanation and solution! The answer at the back of the book is: 2.0 x 10^-10 A.

Explanation / Answer

Known:
B = 1.0 x 10^-15 T
r= 4.0x10^-2m
0 = 4 x 10^-7 H/m

And we know the formula for magnetic field due to a long carrying cunductor is:

B = 0I/2R

Solve for I:

I= (B2r)/(0)

I = (1.0 x 10^-15 T * 2 * 4.0x10^-2m) / (4 x 10^-7 H/m)

I = 2.0 x 10^-10 A

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---