Exam 30: Charges and Currents in Magnetic Fields

A rectangular loop of wire whose dimensions are 15 cm * 25 cm carries a current of 5.0 A. The loop is in a uniform magnetic field of 1.5 T whose direction is parallel to the plane of the loop. The torque acting on the loop is

Two electrons are moving in a uniform magnetic field. The velocity of the first electron is twice the velocity of the second electron. The electron that has the larger circular radius is

The potential energy of a magnetic moment $\mu$ = 1.0 (-2i + j + k) A·m² in a magnetic field given by 1.5 (i + j + k)mT is

Materials with a small negative magnetic susceptibility are called

The SI units associated with magnetic susceptibility are

A 20.0-cm length of wire is aligned along the x axis and carries 5.0 mA of current. The wire is in a region where the uniform magnetic field is given by 1.5(i + 3j + 4k) mT. The net force on the wire is

A Hall voltage is measured across the width of two rods under the same experimental conditions. The only variation is that the thickness of the second rod is twice that of the first rod. The Hall voltage across the second rod will be

For a magnetic material the ratio of the magnetic permeability to the permeability of free space is 3. The ratio of the B_matter/B_external for this material is

A particle with a charge of 1.60 $\times$ 10^-19 and a mass of 1.67 $\times$ 10^-27 kg is found moving in a uniform magnetic field of a strength 1.50 T. The trajectory of the particle is perpendicular to the magnetic field and is circular with a radius of 1.80 cm. The kinetic energy of the particle is

The maximum torque of a 100-turn loop of wire that has an area of 0.15 m² and is carrying 1.5 A of current in a uniform magnetic field of 2.0 T is

A charged particle (q = 1.6 *10^-19 C) enters a mass spectrometer with a speed of 2.5 * 10⁶ m/s. The magnetic field in the spectrometer, 0.25 T, produces a circular motion of the charged particle of radius 2.5 cm. The mass of the charged particle is

Two current-carrying wires produce a repulsive force of magnitude F₀ when the wires are separated by a distance of r₀. The distance between the two wires is changed to 2r₀, resulting in a force whose magnitude is

A 20.0-cm length of wire is aligned along the x axis and carries 5.0 mA of current. The wire is in a region where the uniform magnetic field is given by 1.5(i + 2j) mT. The net force on the wire is

A repulsive force is produced between two parallel wires. The relative directions of the currents in the wires

The current in a wire is directed along the y axis in a uniform magnetic field. The resulting force on the wire is directed along the negative x axis. The magnetic field is directed along the

The magnitude of the torque produced by a magnetic moment $\mu$ = 2.0 (2i + j) A·m² in a magnetic field given by 1.5 (i + k) mT is

The maximum energy difference between the parallel and antiparallel configurations produced by a magnetic moment whose magnitude is $\mu$ = 2.0 A·m² in a magnetic field given by 1.5 mT is

A charged particle is moving in a region where the magnetic field strength is 1.0 T directed in the +x direction and the electric field is 1500 V/m in the +y direction. The particle velocity required for a straight-line trajectory is

A particle with a charge of 1.60 $\times$ 10^-19 and a mass of 1.67 $\times$ 10^-27 kg is found moving in a uniform magnetic field of a strength 1.50 T. The trajectory of the particle is perpendicular to the magnetic field and is circular with a radius of 1.80 cm. The velocity of the particle is

A wire carries 5.00 mA of current in a region where the uniform magnetic field strength is 1.50 mT. If the angle between the wire and the magnetic field is 30°, the net force per unit length on the wire is