Two 173 turn coils, each with a diameter of d = 4.45 m, are placed w = 1.31 m apart, as shown in the figure. A current of 6.99 A is flowing in the wires of both coils; the direction of the current is clockwise for both coils when viewed from the left. What is the magnitude of the magnetic field in the center between the two coils?

The current density in a cylindrical conductor of radius R = 59.9 cm, varies as J(r) = J0r/R (in the region from zero to R), where J0 = 0.511 C/m2.

a) Find the magnitude of the magnetic field at r = 29.95 cm.
b) Find the magnitude of the magnetic field at r = 119.8 cm

Parallel wires, a distance D = 20.6 cm apart, carry a current, i = 3.67 A, in opposite directions as shown in the figure. A circular loop, of radius R = D/2 = 10.3 cm, has the same current flowing in a counterclockwise direction. Determine the magnitude of the magnetic field from the loop and the parallel wires at the center of the loop.

A square ammeter has sides of length l = 3.75 cm. The sides of the ammeter are capable of measuring the magnetic field they are subject to. When the ammeter is clamped around a wire carrying a DC current, as shown in the figure, the average value of the magnetic field measured in the sides is 2.73 G. What is the current in the wire?

You are standing at a spot where the magnetic field of the Earth is horizontal, points due northward, and has magnitude 36.9 μT. Directly above your head, at a height of 12.3 m, a long, horizontal cable carries a steady DC current of 381 A due northward. Calculate the angle θ by which your magnetic compass needle is deflected from true magnetic north by the effect of the cable.

To find the magnitude of the magnetic field in the center between the two coils, we can use the Biot-Savart Law.

The Biot-Savart Law states that the magnetic field at a point due to a current-carrying wire is directly proportional to the current passing through the wire and inversely proportional to the distance from the wire.

The formula for the magnetic field at a point on the axis of a circular coil is given by:

B = (μ₀ * I * N * d) / (2 * R²)

Where:
B is the magnetic field
μ₀ is the permeability of free space (4π * 10^-7 T*m/A)
I is the current in the wire
N is the number of turns in the coil
d is the diameter of the coil
R is the distance from the wire to the point where the magnetic field is measured

In this case, we have two coils with the same current and diameter placed a certain distance apart. The magnetic fields due to each coil will add up at the center point.

We can calculate the magnetic field due to each coil separately and then add them together.

Calculating the magnetic field for the first coil:
N₁ = 173 turns
d₁ = 4.45 m (diameter of the coils)
R₁ = w/2 = 1.31 m / 2

B₁ = (μ₀ * I * N₁ * d₁) / (2 * R₁²)

Calculating the magnetic field for the second coil:
N₂ = 173 turns
d₂ = 4.45 m (diameter of the coils)
R₂ = w/2 = 1.31 m / 2

B₂ = (μ₀ * I * N₂ * d₂) / (2 * R₂²)

Now, we can calculate the total magnetic field at the center point by adding B₁ and B₂:

B_total = B₁ + B₂

Substituting the values into the equations and calculating will give you the magnitude of the magnetic field at the center between the two coils.