A charged particle moves in a region of uniform magnetic field along a helical path (radius= 5.0 cm, pitch = 12 cm, period = 27.6 ms). What is the speed of this particle? ooo ² topl Pitch -2r- B B

▸ Part A What value of magnetic field would make a beam of electrons, traveling to the right at a speed of 5.4×100 m/s. go undeflected through a region where there is a uniform electric field of 9400 V/m pointing vertically up? Express your answer to two significant figures and include the appropriate units. B = 1.7x10-3 T Submit ✓ Correct Part B Previous Answers Part C What is the frequency of the circular orbit of the electrons if the electric field is turned off? Express your answer to two significant figures and include the appropriate units. HA f- Value Submit Request Answer Units ?

A charged particle moves through a velocity selector at constant velocity. The velocity selector is configured with "crossed" electric and magnetic fields of magnitude E = 1.50 x 104 N/C and B = 0.4 T. %3D Hint a. What is the velocity of the charged particle? Velocity of the charged particle is x 104 m/s. b. When the electric field is turned off, the charged particle travels in a circular path of radius 6 mm, as it travels through the magnetic field (still at B = 0.4 T). What is the mass-to-charge ratio of the particle? Hint for (b) Mass-to-charge ratio of the part is kg/C. (Use the "E" notation to enter your answer in scientific notation. For example, to enter 3.14 × 10´ 12".) - 12 enter "3.14E-

R A single wire is formed into circular loop of radius 14.0 cm is carrying a current of 11= 2.98 amps. The wire loop is placed so that the center of the loop is a distance y cm away from a long straight wire carrying current l2= 6.00 amps. If the strength of the magnetic field in the center of the loop is zero, what is the distance y? y = cm

A bar magnet is attached solidly to a frictionless surface and its length is aligned with the x axis. To the right of the first magnet a short distance away is a second bar magnet with its center placed on the x axis and its length perpendicular to the x axis. The second magnet is free to move. Once placed in position at rest, which best describes the initial motion of the second magnet? O The magnet will move away from the fixed magnet. The magnet will not move. The magnet will start to rotate. O The magnet will move toward the fixed magnet.

A 2.0 µC positive charge of speed 6.0 × 106 m/s is moving in a 0.30 T magnetic field, the magnetic field and the charge's velocity are in the same direction as shown. What is the magnitude of the magnetic force on the charge, in Newtons? Your answer needs to have 2 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement. B +

Chapter 28, Problem 020 An electron is accelerated from rest through potential difference V and then enters a region of uniform magnetic field, where it undergoes uniform circular motion. The figure gives the radius r of that motion versus V¹/2. The vertical axis scale is set by rs= 4.0 mm, and the horizontal axis scale is set by V¹/2= 32.9 V¹/2. What is the magnitude of the magnetic field? r (mm) VI/2 V¹/2 (¹/2)