A proton is accelerated from rest through a potential difference of 150 V. It then enters a region of uniform magnetic field and moves in a circular path (radius = 12 cm). What is the magnitude of the magnetic field in this region?
a. 18 mT
b. 12 mT
c. 15 mT
d. 22 mT
e. 10 mT
[Ques. 2] A proton with a kinetic energy of 0.20 keV follows a circular path in a region where the magnetic field is uniform and has a magnitude of 60 mT. What is the radius of this path?
a. 4.1 cm
b. 2.9 cm
c. 3.4 cm
d. 5.1 cm
e. 2.4 cm
[Ques. 3] An electron follows a circular path (radius = 15 cm) in a uniform magnetic field (magnitude = 3.0 G). What is the period of this motion?
a. 0.12 s
b. 1.2 ms
c. 0.18 s
d. 1.8 ms
e. 1.8 s
[Ques. 4] An electron moves in a region where the magnetic field is uniform, has a magnitude of 60 T, and points in the positive x direction. At t = 0 the electron has a velocity that has an x component of 30 km/s, a y component of 40 km/s, and a z component of zero. What is the radius of the resulting helical path?
a. 4.7 mm
b. 18 mm
c. 3.8 mm
d. 2.8 mm
e. 5.7 mm
[Ques. 5] An electron moves in a region where the magnetic field is uniform and has a magnitude of 80 T. The electron follows a helical path which has a pitch of 9.0 mm and a radius of 2.0 mm. What is the speed of this electron as it moves in this region?
a. 48 km/s
b. 28 km/s
c. 20 km/s
d. 35 km/s
e. 8.0 km/s
[Ques. 6] What is the radius of curvature of the path of a 3.0-keV proton in a perpendicular magnetic field of magnitude 0.80 T?
a. 9.9 mm
b. 1.1 cm
c. 1.3 cm
d. 1.4 cm
e. 7.6 mm
[Ques. 7] A charged particle moves in a region of uniform magnetic field along a helical path (radius = 4.0 cm, pitch = 20 cm, period = 2.0 ms). What is the speed of the particle as it moves along this path?
a. 0.13 km/s
b. 0.10 km/s
c. 0.16 km/s
d. 0.23 km/s
e. 0.06 km/s
[Ques. 8] Two single charged ions moving perpendicularly to a uniform magnetic field (B = 0.40 T) with speeds of 5 000 km/s follow circular paths that differ in diameter by 5.0 cm. What is the difference in the mass of these two ions?
a. 2.6 1028 kg
b. 6.4 1028 kg
c. 3.2 1028 kg
d. 5.1 1028 kg
e. 1.1 1028 kg
[Ques. 9] A charged particle (m = 5.0 g, q = 70 C) moves horizontally at a constant speed of 30 km/s in a region where the free fall gravitational acceleration is 9.8 m/s2 downward, the electric field is 700 N/C upward, and the magnetic field is perpendicular to the velocity of the particle. What is the magnitude of the magnetic field in this region?
a. 47 mT
b. zero
c. 23 mT
d. 35 mT
e. 12 mT
[Ques. 10] A charged particle moves in a region of uniform magnetic field along a helical path (radius = 5.0 cm, pitch = 12 cm, period = 5.0 ms). What is the speed of this particle as it moves along this path?
a. 67 m/s
b. 26 m/s
c. 63 m/s
d. 24 m/s
e. 87 m/s
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