Exam 7: Sources of the Magnetic Field

At the instant the negatively charged body is at the origin, the magnetic field at point P due to its motion is in the negative x direction. The charged body must be moving

Four wires carry equal currents along the four parallel edges of a cube. A parallel current-carrying wire through the center of the cube is free to move. The vector that might represent the direction in which the center wire will move is

Two current-carrying wires are perpendicular to each other. The current in one flows vertically upward and the current in the other flows horizontally toward the east. The horizontal wire is 1 m south of the vertical wire. What is the direction of the net magnetic force on the horizontal wire?

Cobalt has a density of 8.90 g/cm³ and a molecular mass of 58.9 g/mol. Its magnetic moment is 1.69 Bohr magnetons (1 Bohr magneton = 9.27 *10^-24 A · m²). What is its saturation magnetization?

A point charge is moving with speed 2 *10⁷ m/s along the x axis. At t = 0, the charge is at x = 0 m and the magnitude of the magnetic field at x = 4 m is B₀. The magnitude of the magnetic field at x = 4m when t = 0.1 $\mu$ s is

If the Biot-Savart relationship d = ( $\mu$ ₀/4 $\pi$ )( * d )/r³ Is used to determine the magnetic field at the point P on the axis of a circular current-carrying loop, the vector is correctly represented by

If the magnetic susceptibility of a material is positive,

Ampère's law is valid

A wire of radius 0.6 cm carries a current of 10 A that is uniformly distributed over its cross section. Calculate the magnetic field strength at r = 0.2 cm divided by that at r = 0.4 cm.

A positively charged body is moving in the negative z direction as shown. The direction of the magnetic field due to the motion of this charged body at point P is

Current-carrying wires are located along two edges of a cube with the directions of the currents as indicated. The vector that indicates the resultant magnetic field at the corner of the cube is

A long conductor carrying current I lies in the xz plane parallel to the z axis. The current travels in the negative z direction, as shown in the figure. The vector that represents the magnetic field at the origin O is

Two long, parallel wires are spaced 1 m apart in air, and you have established a current of 1 A in each. The force per unit length that each wire exerts on the other is

A particle with charge q = 5 $\mu$ C is moving with velocity . At t = 0, it is located at the origin. The magnetic field at at t = 0 is

A circular loop of wire of radius 6.0 cm has 30 turns and lies in the xy plane. It carries a current of 5 A in such a direction that the magnetic moment of the loop is along the x axis. The magnetic field on the x axis at x = 6.0 cm is approximately

A circular loop of wire 1.0 cm in radius carries a current of 30 A. The magnetic field at the center of the loop is

Use the following figure to answer the next problem: -The tightly wound toroid shown consists of 100 turns of wire, each carrying a current I = 3 A. If a = 12 cm and b = 15 cm, the magnetic field at r = 13 cm, due to the current in this toroid, is (µ₀ = 4 $\pi$ *10^-7 N/A²)

Two positively charged bodies are moving in opposite directions on parallel paths that lie in the xz plane. Their speeds are equal and their trajectories are equidistant from the x axis. The magnetic field at the origin, due to the motion of these charged bodies will be

A positively charged body is moving in the positive x direction as shown. The direction of the magnetic field at the origin due to the motion of this charged body is

Calculate the magnetic field and its direction at point P, which is 2.0 cm away from the top wire and 4.0 cm from the bottom wire. Assume both wires are infinitely long and each carries a current of 1.5 A.