Exam 22: Magnetism

A long, straight wire carrying a current is placed along the y-axis. If the direction of the current is in the +y direction, what is the direction of the magnetic field due to this wire?

FIGURE 22-1 -Three particles travel through a region of space where the magnetic field is out of the page, as shown in Figure 22-1. The electric charge of each of the three particles is, respectively,

A wire of a certain length is carrying a current of 2.0 A. It is placed at an angle of 60° with respect to a magnetic field of strength 0.20 T. If the wire experiences a force of 0.40 N, what is the length of the wire?

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

A proton, moving north, enters a magnetic field of a certain strength. Because of this field the proton curves downward. What is the direction of the magnetic field?

Describe diamagnetism.

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?

An electron traveling due North with speed 4 × 10⁵ m/s enters a region where the earth's magnetic field has the magnitude 5 × 10^-5 T and is directed downward at 45° below horizontal. What magnitude force acts on the electron?

An electron is accelerated from rest through a potential difference of 3750 V. It enters a region where the magnetic field is 4.0 mT perpendicular to the velocity of the electron. Calculate the radius of the path this electron will follow.

An electron moving perpendicular to a magnetic field of 3.2 × 10^-2 T moves in a circle of radius 0.40 cm. How fast is this electron moving?

A 1.0-m long wire is carrying a certain amount of current. The wire is placed perpendicular to a magnetic field of strength 0.20 T. If the wire experiences a force of 0.60 N, what is the magnitude of the current moving through the wire?

Two long, parallel wires carry currents of different magnitudes. If the amount of current in each wire is doubled, what happens to the magnitude of the force between the wires?

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. At what point between the two wires are the contributions from the two wires the same?

A proton moving with a velocity of 4.0 × 10⁴ m/s enters a magnetic field of 0.20 T. If the angle between the velocity of the proton and the direction of the magnetic field is 60°, what is the magnitude of the force on the proton?

Long parallel wires separated by 7.5 cm carry 3.3 Amperes each in opposite directions. (a) What magnetic force per length acts on the wires? (b) Find the magnitude of the magnetic field midway between the wires.

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 22-8 -A circular loop of wire of radius 0.50 m is in a uniform magnetic field of 0.30 T. The current in the loop is 2.0 A. What is the magnetic torque when the plane of the loop is perpendicular to the magnetic field?

A wire of a certain length, carrying a current of 2.0 A, is placed perpendicular to a magnetic field of strength 0.20 T. If the wire experiences a force of 0.40 N what is the length of the wire?

FIGURE 22-8 -A rectangular loop of wire, with dimensions shown in Figure 22-8, carries a current of 2 A and is placed in a magnetic field of 0.8 T. The wire rotates in the magnetic field and at one point it is perpendicular to the magnetic field. What is the magnitude of the torque acting on the wire?

FIGURE 22-8 -A circular loop of wire of radius 0.50 m is in a uniform magnetic field of 0.30 T. The current in the loop is 2.0 A. What is the magnetic torque when the plane of the loop is parallel to the magnetic field?