Physics 20 Mcq Study Guide Exam And All Actual Answers.

Two parallel wires are vertical. The one on the left carries a 10-A current upward. The other carries 5-A current downward. Compare the magnitude of the force that each wire exerts on the other. - Answer The two wires exert the same force on each other. Which of the following statements about the force on a charged particle due to a magnetic field are not valid? Check all that apply. It depends on the particle's velocity. It depends on the strength of the external magnetic field. It acts at right angles to the direction of the particle's motion. It depends on the particle's charge. None of the above; all of these statements are valid. - Answer None of the above; all of these statements are valid. For a charged particle, a constant magnetic field can be used to change only the direction of the particle's velocity. only the magnitude of the particle's velocity. both the magnitude and direction of the particle's velocity. None of the above. - Answer only the direction of the particle's velocity. A proton enters a uniform magnetic field that is perpendicular to the proton's velocity What happens to the kinetic energy of the proton? What happens to the kinetic energy of the proton? It increases. It decreases. It stays the same. It depends on the velocity direction. It depends on the B field direction. - Answer It stays the same. No work done, so KE will not change