What current is required in the winding of a long solenoid that has 1000 turns
uniformly distributed over a length of 0.4 m, to produce at the center of the solenoid
a magnetic field of magnitude 1.0 x 10
-4
T?
To determine the required current in the winding of the solenoid, we can use the formula for the magnetic field inside a solenoid:
B = μ₀ * n * I
where:
B is the magnetic field strength,
μ₀ is the permeability of vacuum (4π x 10^-7 T·m/A),
n is the number of turns per unit length (in this case, turns/m),
I is the current in amperes.
In this case, the number of turns per unit length is given as 1000 turns divided by 0.4 m:
n = 1000 turns / 0.4 m
n = 2500 turns/m
The magnetic field strength is given as 1.0 x 10^-4 T. Substituting these values into the formula gives:
1.0 x 10^-4 T = (4π x 10^-7 T·m/A) * (2500 turns/m) * I
Simplifying the equation, we have:
1.0 x 10^-4 T = π x 10^-3 T·m/A * 2500 turns/m * I
1.0 x 10^-4 T = 2.5π x 10^-3 T·m/A * I
Dividing both sides of the equation by (2.5π x 10^-3 T·m/A) gives:
I = (1.0 x 10^-4 T) / (2.5π x 10^-3 T·m/A)
I ≈ 1.27 x 10^-2 A
Therefore, the required current in the winding of the solenoid is approximately 0.0127 A.
To calculate the current required in the winding of a long solenoid to produce a specific magnetic field, we can use the formula for the magnetic field inside a solenoid:
B = μ₀ * n * I
where B is the magnetic field, μ₀ is the permeability of free space (equal to 4π x 10⁻⁷ T⋅m/A), n is the number of turns per unit length (turns/m), and I is the current (A).
In this case, we are given the magnetic field B (1.0 x 10⁻⁴ T), the number of turns n (1000 turns), and the length of the solenoid (0.4 m).
First, we need to calculate the number of turns per unit length:
n = N / L
where N is the total number of turns and L is the length of the solenoid.
n = 1000 turns / 0.4 m
n = 2500 turns/m
Now that we have the value for n, we can rearrange the formula to solve for the current I:
I = B / (μ₀ * n)
Plugging in the values:
I = (1.0 x 10⁻⁴ T) / (4π x 10⁻⁷ T⋅m/A * 2500 turns/m)
Calculating this expression will give you the current required in the winding of the solenoid to produce the desired magnetic field.