A student is given two pieces of iron and told to determine if one or both of the pieces are magnets. First, the student touches an end of one piece to one end of the other. The two pieces of iron attract. Next, the student reverses one of the pieces and again touches the ends together. The two pieces attract again. What does the student definitely know about the initial magnetic properties of the two pieces of iron?

Two particles enter a region in space where there is a constant magnetic field B. Particle 1 has a mass of 2m, speed 3v, and unknown charge of q1. Particle 2 has a mass of m, speed v, and a charge with magnitude q2 = +2e. See figure. While in the field, the radius of motion for particle 1 is 3R and the radius of motion for particle 2 is R. See figure. Find B and q1. The knowns are m, v, R, and e. radius = 3R 3v ● B =? radius= R

An iron (density ρ) rod with length L, cross sectional area A, spans across two parallel, metal train tracks. The tracks are connected to a power supply and have a potential ∆V across them. Between the tracks are placed magnets such that the B-field points directly upwards with strength B. What is the acceleration of the iron rod be the moment it starts from rest? What will acceleration be as a function of speed as it continues? Assume the contact is frictionless between the tracks and the rod so that no force of friction needs to be overcome. What will the top speed of the rod be under these conditions?

A student makes a short electromagnet by winding a wire 213 times around a non-conductive pipe with a radius of 0.0575 m. The coil is connected to a battery producing a current of 7.06 A in the wire. What is the magnitude of the magnetic dipole moment of this device

A small rod magnet has a magnetic field at a distance from it as large as Hom B = 2nz3 Where z is the distance from the magnet on the axis connecting the north pole and south, m is the moment of magnetic dipole. Assuming electrons orbit protons like small rod magnets, determine the m magnetic dipole of an electron orbiting an atom.

A-4.80 uC charge is moving at a constant speed of 6.80 x 105 m/s in the +x-direction relative to a reference frame. At the instant when the point charge is at the origin, what is the magnetic field vector it produces at the following points a point (x 0.500 m, y = 0.500 m, z 0) Select one: B = -1.29x10-77 B = -4.62x10-7 R B = -7.15x10-7 R B = -2.12x10-7↑ B = 3.17x10 6

A charged particle is moving through a B-field and experiences a magnetic force (FR>0). The magnetic force vector is shown below. Choose all the vectors that could represent the B-field. Magnetic force B-field 80° 50° 40° 10° 80 10

For the moment please disregard the moving charge off to the right. The diagram above shows segments of two long straight wires, carrying currents I_1 = 9.57 A and I_2 = 1.64 A respectively. The distance between the wires is 9.01 cm. What is the force on a 1.65-cm segment of wire #2 due to the magnetic field from wire #1?     2.88E-07 N   7.48E-07 N   1.04E-06 N   5.75E-07 N