Version 001 – HW#5 - Magnetism – arts – (00224)
1
This print-out should have 11 questions.
Multiple-choice questions may continue on
the next column or page – find all choices
before answering.
proton is 1.60218 × 10−19 C and its mass is
1.67262 × 10−27 kg.
Charged Particle in a Field 02
001 10.0 points
A charged particle is projected with its initial
velocity parallel to a uniform magnetic field.
What is the resulting path?
2. straight line parallel to the field. correct
Alpha Particle
004 10.0 points
An alpha particle has a mass of 6.6 × 10−27 kg
and is accelerated by a voltage of 0.997 kV.
The charge on a proton is 1.60218×10−19 C.
If a uniform magnetic field of 0.069 T is
maintained on the alpha particle and perpendicular to its velocity, what will be particle’s
radius of curvature?
3. straight line perpendicular to the field.
Correct answer: 0.0928785 m.
4. circular arc.
Magnetic Force Directions 02
005 10.0 points
Two parallel wires carry opposite current as
shown.
1. spiral.
5. parabolic arc.
Field Direction
002 10.0 points
The direction of the magnetic field in a certain
region of space is determined by firing a test
charge into the region with its velocity in
various directions in different trials.
The field direction is
1. the direction of the velocity when the
magnetic force is a maximum.
2. one of the direction of the velocity when
the magnetic field is zero.
3. None of these correct
4. the direction of the magnetic force.
5. perpendicular to the velocity when the
magnetic force is zero.
Proton in a Magnetic Field 02
003 10.0 points
A proton moving at 3.2 × 106 m/s through a
magnetic field of 2.5 T experiences a magnetic
force of magnitude 9.5 × 10−13 N.
What is the angle between the proton’s
velocity and the field? The charge on a
Correct answer: 47.832◦ .
i1
i2
Find the direction of the magnetic force on
i2 due to the magnetic field of i1 .
1. to the right and downward
2. to the right and upward
3. to the right correct
4. to the left
5. into the paper
6. to the left and upward
7. out of the paper
8. to the left and downward
Parallel Wires 01
Version 001 – HW#5 - Magnetism – arts – (00224)
006 10.0 points
Two parallel wires carry equal currents in
the opposite directions. Point A is midway
between the wires, and B is an equal distance
on the other side of the wires.
A
B
2
Correct answer: 16.9401 mA.
Particle Deflection 01
008 10.0 points
A positively charged particle moving parallel
to the z-axis enters a magnetic field (pointing
out of of the page), as shown in the figure
below.
x
~
B
y
v
What is the ratio of the magnitude of the
magnetic field at point A to that at point B?
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
=
4
3
=0
1
3
10
=
3
=
=4
2
=
3
= 3 correct
=
1
2
=2
=
5
2
Long Solenoid
007 10.0 points
What current is required in the windings of
a long solenoid that has 553 turns uniformly
distributed over a length of 0.18 m in order to
produce inside the solenoid a magnetic field of
magnitude 6.54 × 10−5 T? The permeablity
of free space is 1.25664 × 10−6 T m/A.
z
+q
~
B
Figure: ı̂ is in the x-direction, ̂ is
in the y-direction, and k̂ is in the
z-direction.
What is the initial direction of deflection?
b = −k̂
1. F
~ = 0 ; no deflection
2. F
b = −ı̂
3. F
b = +k̂
4. F
b = +̂
5. F
b = +ı̂ correct
6. F
b = −̂
7. F
Particle Deflection 04
009 10.0 points
A positively charged particle moving parallel to the x-axis enters a magnetic field (pointing toward the top of the page), as shown. ı̂ is
in the x-direction, ̂ is in the y-direction, and
k̂ is in the z-direction.
Version 001 – HW#5 - Magnetism – arts – (00224)
y
b = +̂
3. F
~
B
z
v
3
x
b = +k̂
4. F
b = −̂
5. F
+q
b = +ı̂
6. F
~
B
What is the initial direction of deflection?
b = +k̂
1. F
b = +̂
2. F
b = +ı̂
3. F
b = −ı̂
4. F
b = −ı̂
7. F
Particle Deflection 08
011 10.0 points
A negatively charged particle moving at 45◦
angles to both the y-axis and z-axis enters
a magnetic field (pointing towards the righthand side of the page), as shown in the figure.
ı̂ is in the x-direction, ̂ is in the y-direction,
and k̂ is in the z-direction.
z
b = −̂
5. F
~
B
x
~ = 0 ; no deflection
6. F
b = −k̂ correct
7. F
v
Particle Deflection 07
010 10.0 points
A negatively charged particle moving parallel
to the x-axis enters a magnetic field (pointing
toward the right-hand side of the page), as
shown. ı̂ is in the x-direction, ̂ is in the
y-direction, and k̂ is in the z-direction.
y
~
B
z
x
v
~
B
−q
What is the initial direction of deflection?
~ = 0 ; no deflection correct
1. F
b = −k̂
2. F
y
~
B
−q
What is the initial direction of deflection?
b = −ı̂
1. F
1 b
√
2. F =
+ı̂ − k̂
2
b = √1
3. F
+̂ − k̂
2
~
4. F = 0 ; no deflection
b = √1 (+ı̂ − ̂)
5. F
2
b = +ı̂ correct
6. F
b = √1 (−ı̂ + ̂)
7. F
2
1
b = √ (−ı̂ − ̂)
8. F
2
Version 001 – HW#5 - Magnetism – arts – (00224)
1 b
9. F = √
−ı̂ + k̂
2
b = √1
−̂ + k̂
10. F
2
4