Two single charged ions moving perpendicularly to a uniform magnetic field (B = 0.40 T) with speeds of 5000 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. 2] 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. 3] A proton moves around a circular path (radius = 2.0 mm) in a uniform 0.25-T magnetic field. What total distance does this proton travel during a 1.0-s time interval? (m = 1.67 1027 kg, q = 1.6 1019 C)
a. 82 km
b. 59 km
c. 71 km
d. 48 km
e. 7.5 km
[Ques. 4] A 500-eV electron and a 300-eV electron trapped in a uniform magnetic field move in circular paths in a plane perpendicular to the magnetic field. What is the ratio of the radii of their orbits?
a. 2.8
b. 1.7
c. 1.3
d. 4.0
e. 1.0
[Ques. 5] A deuteron is accelerated from rest through a 10-kV potential difference and then moves perpendicularly to a uniform magnetic field with B = 1.6 T. What is the radius of the resulting circular path? (deuteron: m = 3.3 1027 kg, q = 1.6 1019 C)
a. 19 mm
b. 13 mm
c. 20 mm
d. 10 mm
e. 9.0 mm
[Ques. 6] A circular coil (radius = 0.40 m) has 160 turns and is in a uniform magnetic field. When the orientation of the coil is varied through all possible positions, the maximum torque on the coil by magnetic forces is 0.16 N / m when the current in the coil is 4.0 mA. What is the magnitude of the magnetic field?
a. 0.37 T
b. 1.6 T
c. 0.50 T
d. 1.2 T
e. 2.5 T
[Ques. 7] A rectangular coil (0.20 m 0.80 m) has 200 turns and is in a uniform magnetic field of 0.30 T. When the orientation of the coil is varied through all possible positions, the maximum torque on the coil by magnetic forces is 0.080 N / m. What is the current in the coil?
a. 5.0 mA
b. 1.7 A
c. 8.3 mA
d. 1.0 A
e. 42 mA
[Ques. 8] A straight 10-cm wire bent at its midpoint so as to form an angle of 90 carries a current of 10 A. It lies in the xy plane in a region where the magnetic field is in the positive z direction and has a constant magnitude of 3.0 mT. What is the magnitude of the magnetic force on this wire?
a. 3.2 mN
b. 2.1 mN
c. 5.3 mN
d. 4.2 mN
e. 6.0 mN
[Ques. 9] What current must be maintained in a square loop (50 cm on a side) to create a torque of 1.0 N / m about an axis through its center and parallel to one of its sides when a magnetic field of magnitude 70 mT is directed at 40 to the plane of the loop?
a. 66 A
b. 89 A
c. 61 A
d. 75 A
e. 37 A
[Ques. 10] A current of 4.0 A is maintained in a single circular loop having a circumference of 80 cm. An external magnetic field of 2.0 T is directed so that the angle between the field and the plane of the loop is 20. Determine the magnitude of the torque exerted on the loop by the magnetic forces acting upon it.
a. 0.41 N / m
b. 0.14 N / m
c. 0.38 N / m
d. 0.27 N / m
e. 0.77 N / m