You observe an electron moving on your screen in a clockwise circle of radius 6.12 cm, at a constant speed of 6.27 x 10^6 m/s. Suppose that the electrons circular motion is due to the presence of a uniform magnetic field. For this situation above, what is the direction of the magnetic field? Out of the screen (toward you) Into the screen (away from you) Right Left

The accompanying figure shows two long, straight, horizontal wires that are parallel and a distance 2a apart. If both wires carry current I in the same direction, (a) what is the magnetic field at P1? (b) P2?

One long wire carries current 30.0 A to the left along the x axis. A second long wire carries current 50.0 A to the right along the line (y = 0.280 m, z = 0). (a) Where in the plane of the two wires is the total magnetic field equal to zero? (b) A particle with a charge of 2.00 C is moving with a velocity of 150iMm/s along the line (y = 0.100 m, z = 0). Calculate the vector magnetic force acting on the particle. (c) What If? A uniform electric field is applied to allow this particle to pass through this region undetected. Calculate the required vector electric field.

A proton (charge +e, mass mp), a deuteron (charge +e, mass 2mp), and an alpha particle (charge +2e, mass 4mp) are accelerated from rest through a common potential difference V. Each of the particles enters a uniform magnetic field B, with its velocity in a direction perpendicular to B. The proton moves in a circular path of radius p. In terms of p, determine (a) the radius rd of the circular orbit for the deuteron and (b) the radius r for the alpha particle.

A charged particle is moving perpendicular to a magnetic field in a circle with a radius r. (i) An identical particle enters the field, with v perpendicular to B, but with a higher speed than the first particle. Compared with the radius of the circle for the first particle, is the radius of the circular path for the second particle (a) smaller, (b) larger, or (c) equal in size? (ii) The magnitude of the magnetic field is increased. From the same choices, compare the radius of the new circular path of the first particle with the radius of its initial path.

A toroid with an inner radius of 20 cm and an outer radius of 22 cm is tightly wound with one layer of wire that has a diameter of 0.25 mm. (a) How many turns are there on the toroid? (b) If the current through the toroid windings is 2.0 A, what is the strength of the magnetic field at the center of the toroid?

Magnetic Field Due to a Long, Straight Wire In a laboratory, you measure the magnitude of the magnetic field generated by a long, straight wire, and you plot your resultsB as a function of position r. Which of the graphs in Figure 31.15 best represents the magnetic field due to a long, straight wire?

A packed bundle of 100 long, straight, insulated wires forms a cylinder of radius R = 0.500 cm. If each wire carries 2.00 A, what are (a) the magnitude and (b) the direction of the magnetic force per unit length acting on a wire located 0.200 cm from the center of the bundle? (c) What If? Would a wire on the outer edge of the bundle experience a force greater or smaller than the value calculated in parts (a) and (b)? Give a qualitative argument for your answer.

An infinitely long wire carrying a current I is bent at a right angle as shown in Figure P22.30. Determine the magnetic field at point P, located a distance x from the corner of the wire. Figure P22.30

A cosmic-ray electron moves at 7.5 × 106 m/sinches perpendicular to Earth’s magnetic field at an altitude queer the field strength is 1.0 × 105T. What is the radius of the circular path the electron follows?