Exam 22: Magnetism

An electron moving in the positive y direction, at right angles to a magnetic field, experiences a magnetic force in the negative x direction. What is the direction of the magnetic field?

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

An electron, moving west, enters a magnetic field of a certain strength. Because of this field the electron curves upward. What is the direction of the magnetic field?

A proton moving at 5.0 × 10⁴ m/s horizontally enters a region where a magnetic field of 0.12 T is present, directed vertically downward. What magnitude force acts on the proton?

A 2-m long wire is carrying a current of 2 A. The wire is placed at an angle of 60° with respect to a magnetic field. If the wire experiences a force of 0.2 N, what is the strength of the magnetic field?

How much current must pass through a 400 turn coil 4.0 cm long to generate a 1.0-T magnetic field at the center?

At a given location the direction of the magnetic field is the direction that the north pole of a compass points when placed at that location.

A long straight wire carrying 15. A is perpendicular to a 0.10 T field. Find the force per meter on the wire.

What is the magnetic field at the center of a circular loop of wire of radius 4.0 cm when a current of 2.0 A flows in the wire?

The magnetic field at a point P, a certain distance from a long wire carrying a current of 2.0 A, is 1.2 × 10^-6 T. How far is P from the center of the wire?

The magnetic force on a circular loop of wire of radius r carrying current I around it is zero N.

FIGURE 22-5 -A metal bar of mass m and length L is suspended from two conducting wires, as shown in the sketch in Figure 22-5. A uniform magnetic field points vertically downward. Choose the expression that best describes the condition satisfied by the angle θ that the suspending wires make with the vertical when the bar carries a current I.

The magnetic field at a distance of 2 cm from a current carrying wire is 4 μT. What is the magnetic field at a distance of 1 cm from the wire?

An ion enters a mass spectrometer which has a 0.18 Tesla field perpendicular to an electric field of 1.6 kV/m and selects a velocity. The same magnetic field is then used to deflect the singly charged ion into a circular path of radius 12.5 cm. (a) What velocity was selected? (b) What was the ion mass?

A solenoid of 200 turns carrying a current of 2 A has a length of 25 cm. What is the magnitude of the magnetic field at the center of the solenoid?

A proton is accelerated from rest through 500. V. It enters a magnetic field of 0.300 T oriented perpendicular to its direction of motion. Determine: (a) the radius of the path it follows. (b) the frequency with which it moves around this path.

Ten meters away from a long straight wire, the field is 10^-4 Tesla. What current flows through the wire?

FIGURE 22-8 -A rectangular loop of wire, with dimensions as shown in Figure 22-8, carrying a 2-A current is placed in a magnetic field of 0.8 T. The loop rotates in the magnetic field and at one point makes a 30° angle with the magnetic field. What is the magnitude of the torque acting on the wire?

A wire carrying a 2-A current is placed at an angle of 60° with the respect to a magnetic field of strength 0.2 T. If the length of the wire is 0.6 m what is the magnitude of the magnetic force acting on the wire?

FIGURE 22-8 -A rectangular loop of wire carrying a 4.0-A current and with certain dimensions is placed in a magnetic field of 0.60 T. The magnitude of the torque acting on this wire when it makes a 60° angle with the field is 1.1 Nm. What is the area of this wire?