(whose trail is not visible) splits into 3 other particles, including those that follow paths A and B. (a) What is the sign of the
charge of the particle that follows path A? (b) What is the sign of the charge of the particle that follows path B? (c) Explain
your answers.
(a) i. Positive
ii. Negative
iii. Neutral
(b) i. Positive
ii. Negative
iii. Neutral
(c)
C.15Some computer monitors are made with cathode ray tubes (CRTs) like a traditional TV screen. The glowing image on a CRT
monitor is created by a steerable stream of electrons that travel from the back of the tube to strike tiny phosphors on the
inside of the screen surface. When a bar magnet is placed near a CRT computer monitor, it causes severe (and possibly
lasting) distortion of the image displayed on the screen. Describe what causes the distortion.C.16A focused magnetic field of variable strength is
used to "steer" electrons in a television tube
(CRT). The electrons emerge in a stream from
a "gun" that has accelerated them across a
potential difference. A magnetic field can
deflect the beam of electrons in various
directions. They then travel to the tube's front
inside surface on the TV screen, where they
strike red, green, or blue phosphors and cause
them to glow, creating part of one pixel in a
picture display (actual color tubes use three
guns, one for each color). Use the orientation of the components as shown in the illustration to answer these questions. (a) In
what direction should the magnetic field point to deflect the electron beam upward, toward the top of the tube? (b) A TV tube
plays the electron beam over its picture screen in a raster pattern, moving it from one side of the screen to the other at the
very top of the tube, then all the way across the screen at a lower point, and again and again at still lower points, until the
whole screen is painted with sideways sweeps. A second magnetic field of varying strength, which is not shown in the
illustration, deflects the beam from side to side at each one of its vertical positions. Suppose a beam is heading straight
toward the left in the illustration (it is not deflected vertically). In what direction would the second field have to point to deflect
the beam toward you?
i. Right
ii. Left
iii. Up
iv. Down
v. Toward you
vi. Away from youi. Right
ii. Left
iii. Up
iv. Down
v. Toward you
vi. Away from you
C.17A charged particle is moving freely through a uniform field. How can you tell if the field is an electric field or a magnetic field?C.18Cosmic "rays", which are charged particles approaching the Earth from space, strike the planet more frequently at the poles
than at the equator. Why is this?C.19A current-carrying wire is placed in a uniform magnetic field, but there is no magnetic force on it. How is this possible?Section Problems
Section 0 - Introduction
0.1 Use the simulation in the first interactive problem, and the initial conditions, in this section to answer the following questions.
(a) Does the moving particle travel in a straight line or a curve? (b) Is the particle's speed changing? (c) Is the particle
accelerating?
(a) Straight line Curve
(b) Yes No
(c) Yes No(^530) Copyright 2007 Kinetic Books Co. Chapter 28 Problems