Question

You would like a solenoid that is 32 cm long to produce a magnetic field of 0.78 T when it carries a

current of 7.7 A. How many loops should this solenoid have?
​

Answer 1

N = 25795 loops

Step-by-step explanation:

The magnetic field of a solenoid can be calculated by using the following formula:

`B = (\mu NI)/(L)\\N = (BL)/(\mu I)`

where,

N = No. of loops = ?

B = Magnetic Field = 0.78 T

L = Length of solenoid = 32 cm = 0.32 m

I = Current = 7.7 A

μ = permeability of free space = 4π x 10⁻⁷ N/A²

Therefore,

`N = ((0.78\ T)(0.32\ m))/((4\pi\ x\ 10^(-7)\ N/A^2)(7.7\ A))\\`

N = 25795 loops