Exam 28: Sources of Magnetic Field

Four long parallel wires each carry 2.0 A in the same direction. They are parallel to the z-axis, and they pass through the corners of a square of side 4.0 cm positioned in the x-y plane. What magnetic field does one of the wires experience due to the other wires?

FIGURE 28-2 -Fig. 28-2 shows four different sets of wires that cross each other without actually touching. The magnitude of the current is the same in all four cases, and the directions of current flow are as indicated. For which configuration will the magnetic field at the center of the square formed by the wires be equal to zero?

A semicircular wire of radius R connects two straight wire segments. If a current I flows along the wire, the magnitude of the magnetic field at the center of the semicircular wire due to the current in the semicircular wire is

A circular loop of wire of radius 10 cm carries a current of 6A. The magnitude of the magnetic field at the center of the loop is

What is the value of the magnetic field at the center of a square wire of length a on the side, if the current in the wire is I?

Two long parallel wires are placed side-by-side on a horizontal table. If the wires carry current in opposite directions,

If two identical wires carrying a certain current in the same direction are placed parallel to each other, they will experience a force of repulsion.

FIGURE 28-1 -Fig. 28-1 above shows two long wires carrying equal currents I₁ and I₂ flowing in opposite directions. Which of the arrows labeled A to D correctly represents the direction of the magnetic field due to the wires at a point located at an equal distance d from each wire?

Describe paramagnetism

Two long parallel wires are placed side-by-side on a horizontal table. If the wires carry current in the same direction,

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnetic field midway between the two wires?

Aluminum has a magnetic susceptibility χ = 1.7 × 10^-5 at T = 300 K. What will be the magnetization of a small sample of aluminum placed in a 1.5 T magnetic field at T = 150 K?

Two parallel wires carry currents in the same direction. The direction of the force on one wire

A solenoid with 400 turns has a radius of 0.040 m and is 40 cm long. If this solenoid carries a current of 12 A, what is the magnitude of the magnetic field at the center of the solenoid?

A straight wire carries a 12-A current eastward and a second straight wire carries a 14-A current westward. The wires are separated by a distance of 42 cm. The force on a 6.4 m length of one of the wires is

In using Ampere's law, the integral must be evaluated

The magnitude of the magnetic field inside a solenoid is inversely proportional to the current flowing through the solenoid.

The field near a long straight wire carrying a current is inversely proportional to the current flowing through the wire.

FIGURE 28-7 -Two parallel segments of wire, of length L = 0.8m are positioned a distance d = 1 m apart as shown in Fig. 28-7. Calculate the magnetic field at point P located half-way between the two segments. (Each segment carries and electric current I = 10 A in the directions indicated.)

A small cylinder made of a diamagnetic material is brought near a bar magnet. One end of the cylinder is brought near the North pole of the magnet and is repelled. What happens when the other end of the cylinder is brought near the North pole of the magnet?