Magnetic Field
1. A charged particle is launched with a velocity of 5.2 × 104 m/s at an angle of 35° with respect
to a 0.0045-T magnetic field. If the magnetic field exerts a force of 0.0026 N on the particle,
determine the magnitude of the charge on the particle.
A) 11 µC
B) 15 µC
C) 19 µC
D) 23 µC
E) 27 µC
2. An electron is moving with a speed of 3.5 × 105 m/s when it encounters a magnetic field of
0.60 T. The direction of the magnetic field makes an angle of 60.0° with respect to the velocity
of the electron. What is the magnitude of the magnetic force on the electron?
A) 4.9 × 10–13 N
B) 3.2 × 10–13 N
C) 1.7 × 10–13 N
D) 3.4 × 10–14 N
E) 2.9 × 10–14 N
3. A particle with a mass of 6.64 × 10–27 kg and a charge of +3.20 × 10–19 C is accelerated from
rest through a potential difference of 2.45 × 106 V. The particle then enters a uniform 1.60-T
magnetic field. If the particle's velocity is perpendicular to the magnetic field at all times, what
is the magnitude of the magnetic force exerted on the particle?
A) zero newtons
B) 1.14 × 10–10 N
C) 6.55 × 10–10 N
D) 4.09 × 10–11 N
E) 7.87 × 10–12 N
,4. A mass spectrometer is used to separate two isotopes of uranium with masses m1 and m2
where m2 > m1. The two types of uranium atom exit an ion source S with the same charge of +e
and are accelerated through a potential difference V. The charged atoms then enter a constant,
uniform magnetic field B as shown. If r1 = 0.5049 m and r2 = 0.5081 m, what is the value of the
ratio m1/m2?
A) 0.9984
B) 0.9937
C) 0.9874
D) 0.9812
E) 0.9749
5. A 0.0150-m wire oriented horizontally between the poles of an electromagnet carries a direct
current of 9.5 A. The angle between the direction of the current and that of the magnetic field is
25.0° as shown. If the magnetic field strength is 0.845 T, what is the magnitude and direction of
the magnetic force on the wire between the poles?
A) 1.17 N, upward
B) 0.330 N, downward
C) 0.0509 N, upward
D) 0.120 N, downward
E) 0.495 N, upward
, 6. A long, straight wire carries a 6.0-A current that is directed in the positive x direction. When a
uniform magnetic field is applied perpendicular to a 3.0-m segment of the wire, the magnetic
force on the segment is 0.36 N, directed in the negative y direction, as shown. What are the
magnitude and direction of the magnetic field?
A) 0.020 T, out of the paper
B) 0.020 T, into the paper
C) 0.060 T, out of the paper
D) 0.060 T, into the paper
E) 0.65 T, out of the paper
7. A loop of wire with a weight of 0.55 N is oriented vertically and carries a current I = 2.25 A.
A segment of the wire passes through a magnetic field directed into the plane of the page as
shown. The net force on the wire is measured using a balance and found to be zero. What is the
magnitude of the magnetic field?
A) zero tesla
B) 0.51 T
C) 0.84 T
D) 1.2 T
E) 4.5 T
8. A circular coil consists of 5 loops each of diameter 1.0 m. The coil is placed in an external
magnetic field of 0.5 T. When the coil carries a current of 4.0 A, a torque of magnitude 3.93 N-
m acts on it. Determine the angle between the normal to the plane of the coil and the direction of
the magnetic field.
A) 0°
B) 30°
C) 45°
D) 60°
E) 90°
1. A charged particle is launched with a velocity of 5.2 × 104 m/s at an angle of 35° with respect
to a 0.0045-T magnetic field. If the magnetic field exerts a force of 0.0026 N on the particle,
determine the magnitude of the charge on the particle.
A) 11 µC
B) 15 µC
C) 19 µC
D) 23 µC
E) 27 µC
2. An electron is moving with a speed of 3.5 × 105 m/s when it encounters a magnetic field of
0.60 T. The direction of the magnetic field makes an angle of 60.0° with respect to the velocity
of the electron. What is the magnitude of the magnetic force on the electron?
A) 4.9 × 10–13 N
B) 3.2 × 10–13 N
C) 1.7 × 10–13 N
D) 3.4 × 10–14 N
E) 2.9 × 10–14 N
3. A particle with a mass of 6.64 × 10–27 kg and a charge of +3.20 × 10–19 C is accelerated from
rest through a potential difference of 2.45 × 106 V. The particle then enters a uniform 1.60-T
magnetic field. If the particle's velocity is perpendicular to the magnetic field at all times, what
is the magnitude of the magnetic force exerted on the particle?
A) zero newtons
B) 1.14 × 10–10 N
C) 6.55 × 10–10 N
D) 4.09 × 10–11 N
E) 7.87 × 10–12 N
,4. A mass spectrometer is used to separate two isotopes of uranium with masses m1 and m2
where m2 > m1. The two types of uranium atom exit an ion source S with the same charge of +e
and are accelerated through a potential difference V. The charged atoms then enter a constant,
uniform magnetic field B as shown. If r1 = 0.5049 m and r2 = 0.5081 m, what is the value of the
ratio m1/m2?
A) 0.9984
B) 0.9937
C) 0.9874
D) 0.9812
E) 0.9749
5. A 0.0150-m wire oriented horizontally between the poles of an electromagnet carries a direct
current of 9.5 A. The angle between the direction of the current and that of the magnetic field is
25.0° as shown. If the magnetic field strength is 0.845 T, what is the magnitude and direction of
the magnetic force on the wire between the poles?
A) 1.17 N, upward
B) 0.330 N, downward
C) 0.0509 N, upward
D) 0.120 N, downward
E) 0.495 N, upward
, 6. A long, straight wire carries a 6.0-A current that is directed in the positive x direction. When a
uniform magnetic field is applied perpendicular to a 3.0-m segment of the wire, the magnetic
force on the segment is 0.36 N, directed in the negative y direction, as shown. What are the
magnitude and direction of the magnetic field?
A) 0.020 T, out of the paper
B) 0.020 T, into the paper
C) 0.060 T, out of the paper
D) 0.060 T, into the paper
E) 0.65 T, out of the paper
7. A loop of wire with a weight of 0.55 N is oriented vertically and carries a current I = 2.25 A.
A segment of the wire passes through a magnetic field directed into the plane of the page as
shown. The net force on the wire is measured using a balance and found to be zero. What is the
magnitude of the magnetic field?
A) zero tesla
B) 0.51 T
C) 0.84 T
D) 1.2 T
E) 4.5 T
8. A circular coil consists of 5 loops each of diameter 1.0 m. The coil is placed in an external
magnetic field of 0.5 T. When the coil carries a current of 4.0 A, a torque of magnitude 3.93 N-
m acts on it. Determine the angle between the normal to the plane of the coil and the direction of
the magnetic field.
A) 0°
B) 30°
C) 45°
D) 60°
E) 90°
