Serway Cap 29

Chapter 29

Magnetic Fields

Multiple-Choice

1. An electron has a velocity of 6.0 ( 106 m/s in the positive x direction at a point where the magnetic field has the components Bx = 3.0 T, By = 1.5 T and Bz = 2.0 T. What is the magnitude of the acceleration of the electron at this point?

a. 2.1 × 1018 m/s2
b. 1.6 × 1018 m/s2
c. 2.6 × 1018 m/s2
d. 3.2 × 1018 m/s2e. 3.7 × 1018 m/s2

2. A particle (q = 5.0 nC, m = 3.0 µg) moves in a region where the magnetic field has components Bx = 2.0 mT, By = 3.0 mT, and Bz = –4.0 mT. At an instant when the speed of the particle is 5.0 km/s and the direction of its velocity is 120( relative to the magnetic field, what is the magnitude of the acceleration of the particle?

a. 33 m/s2
b. 17 m/s2c. 39 m/s2
d. 25 m/s2
e. 45 m/s2

3. A particle (q = –4.0 µC, m = 5.0 mg) moves in a uniform magnetic field with a velocity having a magnitude of 2.0 km/s and a direction that is 50( away from that of the magnetic field. The particle is observed to have an acceleration with a magnitude of 5.8 m/s2. What is the magnitude of the magnetic field?

a. 5.3 mT
b. 4.9mT
c. 5.1 mT
d. 4.7 mT
e. 3.6 mT

4. An electron moving in the positive x direction experiences a magnetic force in the positive z direction. If Bx = 0, what is the direction of the magnetic field?

a. negative y direction
b. positive y direction
c. negative z direction
d. positive z direction
e. negative x direction

5. A 2.0-C chargemoves with a velocity of (2.0i + 4.0j + 6.0k) m/s and experiences a magnetic force of (4.0i – 20j + 12k) N. The x component of the magnetic field is equal to zero. Determine the y component of the magnetic field.

a. –3.0 T
b. +3.0 T
c. +5.0 T
d. –5.0 T
e. +6.0 T

6. A 2.0-C charge moves with a velocity of (2.0i + 4.0j + 6.0k) m/s and experiences a magneticforce of (4.0i – 20j + 12k) N. The x component of the magnetic field is equal to zero. Determine the z component of the magnetic field.

a. –3.0 T
b. +3.0 T
c. +5.0 T
d. –5.0 T
e. +6.0 T

7. A particle (mass = 2.0 mg, charge = –6.0 µC) moves in the positive direction along the x axis with a velocity of 3.0 km/s. It enters a magnetic field of(2.0i + 3.0j + 4.0k) mT. What is the acceleration of the particle?

a. (36j – 27k) m/s2
b. (–36j + 27k) m/s2
c. (–24j + 18k) m/s2
d. (24j – 18k) m/s2
e. (24j – 27k) m/s2

8. A particle (mass = 6.0 mg) moves with a speed of 4.0 km/s in a direction that makes an angle of 37° above the positive x axis in the xy plane. At the instant it enters a magnetic field of (5.0i) mT it experiencesan acceleration of (8.0k) m/s2. What is the charge of the particle?

a. –4.8 µC
b. 4.0 µC
c. –4.0 µC
d. 4.8 µC
e. –5.0 µC

9. A positively charged particle has a velocity in the negative z direction at point P. The magnetic force on the particle at this point is in the negative y direction. Which one of the following statements about the magnetic field at pointP can be determined from this data?

a. Bx is positive.
b. Bz is positive.
c. By is negative.
d. By is positive.
e. Bx is negative.

10. A charged particle (mass = 4.0 µg, charge = 5.0 µC) moves in a region where the only force on it is magnetic. What is the magnitude of the acceleration of the particle at a point where the speed of the particle is 5.0 km/s,the magnitude of the magnetic field is 8.0 mT, and the angle between the direction of the magnetic field and the velocity of the particle is 60(?

a. 39 km/s2
b. 43 km/s2
c. 48 km/s2
d. 52 km/s2
e. 25 km/s2

11. A charged particle (mass = M, charge = Q > 0) moves in a region of space where the magnetic field has a constant magnitude of B and a downward...