Question 1

If an electron is released at the equator and falls toward the Earth under the influence of gravity, the magnetic force on the electron will be toward the:

Accepted Answer

C

Question 2

A deuteron, with the same charge but twice the mass of a proton, moves with a speed of 6.0 * 10⁵m/s perpendicular to a uniform magnetic field of 0.20 T. Which of the paths described below would it follow? (q_p = 1.6 * 10 ^- ¹⁹ C and m_d = 3.34 *10 ^- ²⁷ kg)

Accepted Answer

The correct answer is A because the deuteron has twice the mass of a proton, so it will have half the radius of curvature in the magnetic field.

Question 3

A current in a long, straight wire produces a magnetic field. The magnetic field lines:

Accepted Answer

The magnetic field lines produced by a current in a long, straight wire form concentric circles around the wire, as described by the right-hand rule.

Question 4

A proton is released such that it has an initial speed of 5.0 *10⁵ m/s from left to right across the page. A magnetic field of 1.2 T is present at an angle of 30° to the horizontal direction (or positive x axis). What is the magnitude of the force experienced by the proton? (q_p = 1.6 *10^-¹⁹C)

Accepted Answer

The force on a charged particle moving in a magnetic field is given by F = qvBsinθ. Substituting the given values: F = (1.6 × 10^-19 C)(5.0 × 10^5 m/s)(1.2 T)sin(30°) = 4.8 × 10^-14 N.

Question 5

Electrical charges and magnetic poles have many similarities, but one difference is:

Accepted Answer

Magnetic poles always come in pairs (north and south), and cannot be isolated like electric charges can.

Question 6

Two singly ionized isotopes, X and Y, of the same element move with the same speed perpendicular to a uniform magnetic field. Isotope X follows a path of radius 3.35 cm while isotope Y moves along a path 3.43 cm in radius. What is the ratio of the two isotope masses, m_Y/m_X?

Accepted Answer

The radius of the path in a magnetic field is proportional to the mass of the ion. Therefore, the ratio of the radii is equal to the ratio of the masses. Thus, m_Y/m_X = 3.43 cm / 3.35 cm = 1.02.

Question 7

A bar magnet is attached solidly to a frictionless surface and its length is aligned with the x axis. To the right of the first magnet a short distance away is a second bar magnet with its center placed on the x axis and its length perpendicular to the x axis. The second magnet is free to move. Once placed in position at rest, which best describes the initial motion of the second magnet?

Accepted Answer

The second magnet will start to rotate due to the magnetic field produced by the first magnet. This is because the poles of the second magnet will experience forces in opposite directions due to the magnetic field, causing it to rotate to align with the field lines of the first magnet.

Question 8

A proton moves across the Earth's equator in a northwesterly direction. At this point the Earth's magnetic field has a direction due north and is parallel to the surface. What is the direction of the force acting on the proton at this instant?

Accepted Answer

The answer of A proton moves across the Earth's equator...

Question 9

A proton, which moves perpendicular to a magnetic field of 0.60 T in a circular path of radius 0.080 m, has what speed? (q_p = 1.6 *10^-¹⁹ C and m_p = 1.67 *10^-²⁷ kg)

Accepted Answer

The speed of the proton can be calculated using the formula for the radius of the circular path in a magnetic field: r = (m*v)/(q*B). Solving for v gives v = (r*q*B)/m. Substituting the given values: r = 0.080 m, q = 1.6 x 10^-19 C, B = 0.60 T, and m = 1.67 x 10^-27 kg, we find v ≈ 4.6 x 10^6 m/s.

Question 10

An electron which moves with a speed of 7.5 *10³ m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 *10^-¹⁹ C)

Accepted Answer

The force on a charged particle moving parallel to a magnetic field is zero because the magnetic force is perpendicular to the velocity and magnetic field.

Question 11

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

Accepted Answer

The magnetic force on a charged particle is given by F = qvBsinθ, where θ is the angle between the velocity and the magnetic field. The force is maximum when sinθ is maximum, which occurs at 90°.

Question 12

There is a magnetic force on a particle. It is possible that the particle is:

Accepted Answer

A magnetic force can act on a charged particle moving perpendicular to a magnetic field, regardless of whether it is part of a wire or not.

Question 13

An electron is released such that its initial velocity is from right to left across this page. The electron's path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field. What is the direction of this field?

Accepted Answer

The direction of the magnetic field can be determined using the right-hand rule. If the fingers of the right hand point in the direction of the electron's initial velocity (from right to left), and the palm of the hand is facing down (toward the bottom edge of the page), then the direction of the magnetic force will be out of the page, perpendicular to both the velocity and field directions. Therefore, the direction of the magnetic field must be in the opposite direction, which is into the page.

Question 14

A proton moving at a speed of 3.8 *10⁶ m/s cuts across the lines of a magnetic field at an angle of 40°. The strength of the field is 0.25 *10^-⁴ T. What is the magnitude of the force acting on the proton? (q_p = 1.6 *10^-¹⁹ C)

Accepted Answer

The answer of A proton moving at a speed of...

Question 15

A stationary positive charge +Q is located in a magnetic field B, which is directed toward the right as indicated. The direction of the magnetic force on Q is:

Accepted Answer

The answer of A stationary positive charge +Q is located...

Question 16

Assume that a uniform magnetic field is directed into this page. If a proton is released with an initial velocity directed from the bottom edge to the top edge of the page, which of the following describes the direction of the resultant force acting on the proton?

Accepted Answer

The direction of the magnetic force on a charged particle is given by the right-hand rule. If you point your thumb in the direction of the particle's velocity and your fingers in the direction of the magnetic field, then the resulting force will be perpendicular to both and pointed in the direction your palm is facing. In this case, the proton's velocity is to the top of the page and the magnetic field is into the page, so if you point your thumb up and your fingers into the page, then your palm is facing to the left, which is the direction of the resultant force on the proton.

Question 17

A proton moving with a speed of 6.0 *10⁵ m/s perpendicular to a uniform magnetic field of 0.20 T will follow which of the paths described below? (q_p = 1.6 *10^-¹⁹ C and m_p = 1.67 * 10^-²⁷ kg)

Accepted Answer

The answer of A proton moving with a speed of...

Question 18

The right-hand rule allows one to find a property of the interaction of a magnetic field with a charged particle. The right-hand rule applied to moving charges:

Accepted Answer

The right-hand rule is used to determine the direction of the magnetic force on a moving charge in a magnetic field. It applies to both positive and negative charges, but the direction of the force is opposite for negative charges.

Question 19

Three identical bar magnets, each 2 cm long, are placed in a straight line on a frictionless surface with their ends equally spaced with 2 cm between ends. They are constrained so they cannot rotate, but they can slide along the straight line. The left magnet has its north pole nearest the north pole of the middle magnet, and the right magnet has its south pole toward the middle magnet's south pole. Once they are in place and released from rest, which of the following best describes the motion of the magnets?

Accepted Answer

The end magnets will experience repulsive forces from the center magnet due to like poles facing each other (north-north and south-south), causing them to move away from the center magnet.

Question 20

The path of a charged particle moving perpendicular to a uniform magnetic field will be a:

Accepted Answer

The path of a charged particle moving perpendicular to a uniform magnetic field is a circle. This is because the magnetic force on the particle is always perpendicular to its velocity, so it causes the particle to move in a circle.

Quiz 20: Magnetic Fields and Forces

If an electron is released at the equator and falls toward the Earth under the influence of gravity, the magnetic force on the electron will be toward the:

A deuteron, with the same charge but twice the mass of a proton, moves with a speed of 6.0 * 10⁵m/s perpendicular to a uniform magnetic field of 0.20 T. Which of the paths described below would it follow? (q_p = 1.6 * 10 ^- ¹⁹ C and m_d = 3.34 *10 ^- ²⁷ kg)

A current in a long, straight wire produces a magnetic field. The magnetic field lines:

A proton is released such that it has an initial speed of 5.0 10⁵ m/s from left to right across the page. A magnetic field of 1.2 T is present at an angle of 30° to the horizontal direction (or positive x axis) . What is the magnitude of the force experienced by the proton? (q_p = 1.6 10^-¹⁹C)

Electrical charges and magnetic poles have many similarities, but one difference is:

Two singly ionized isotopes, X and Y, of the same element move with the same speed perpendicular to a uniform magnetic field. Isotope X follows a path of radius 3.35 cm while isotope Y moves along a path 3.43 cm in radius. What is the ratio of the two isotope masses, m_Y/m_X?

A proton moves across the Earth's equator in a northwesterly direction. At this point the Earth's magnetic field has a direction due north and is parallel to the surface. What is the direction of the force acting on the proton at this instant?

A proton, which moves perpendicular to a magnetic field of 0.60 T in a circular path of radius 0.080 m, has what speed? (q_p = 1.6 10^-¹⁹ C and m_p = 1.67 10^-²⁷ kg)

An electron which moves with a speed of 7.5 10³ m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 10^-¹⁹ C)

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

There is a magnetic force on a particle. It is possible that the particle is:

An electron is released such that its initial velocity is from right to left across this page. The electron's path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field. What is the direction of this field?

A proton moving at a speed of 3.8 10⁶ m/s cuts across the lines of a magnetic field at an angle of 40°. The strength of the field is 0.25 10^-⁴ T. What is the magnitude of the force acting on the proton? (q_p = 1.6 *10^-¹⁹ C)

A stationary positive charge +Q is located in a magnetic field B, which is directed toward the right as indicated. The direction of the magnetic force on Q is:

Assume that a uniform magnetic field is directed into this page. If a proton is released with an initial velocity directed from the bottom edge to the top edge of the page, which of the following describes the direction of the resultant force acting on the proton?

A proton moving with a speed of 6.0 10⁵ m/s perpendicular to a uniform magnetic field of 0.20 T will follow which of the paths described below? (q_p = 1.6 10^-¹⁹ C and m_p = 1.67 * 10^-²⁷ kg)

The right-hand rule allows one to find a property of the interaction of a magnetic field with a charged particle. The right-hand rule applied to moving charges:

The path of a charged particle moving perpendicular to a uniform magnetic field will be a:

Quiz 20: Magnetic Fields and Forces

If an electron is released at the equator and falls toward the Earth under the influence of gravity, the magnetic force on the electron will be toward the:

A deuteron, with the same charge but twice the mass of a proton, moves with a speed of 6.0 * 105 m/s perpendicular to a uniform magnetic field of 0.20 T. Which of the paths described below would it follow? (qp = 1.6 * 10 - 19 C and md = 3.34 *10 - 27 kg)

A current in a long, straight wire produces a magnetic field. The magnetic field lines:

A proton is released such that it has an initial speed of 5.0 *105 m/s from left to right across the page. A magnetic field of 1.2 T is present at an angle of 30° to the horizontal direction (or positive x axis) . What is the magnitude of the force experienced by the proton? (qp = 1.6 *10-19 C)

Electrical charges and magnetic poles have many similarities, but one difference is:

Two singly ionized isotopes, X and Y, of the same element move with the same speed perpendicular to a uniform magnetic field. Isotope X follows a path of radius 3.35 cm while isotope Y moves along a path 3.43 cm in radius. What is the ratio of the two isotope masses, mY/mX?

A proton moves across the Earth's equator in a northwesterly direction. At this point the Earth's magnetic field has a direction due north and is parallel to the surface. What is the direction of the force acting on the proton at this instant?

A proton, which moves perpendicular to a magnetic field of 0.60 T in a circular path of radius 0.080 m, has what speed? (qp = 1.6 *10-19 C and mp = 1.67 *10-27 kg)

An electron which moves with a speed of 7.5 *103 m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 *10-19 C)

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

There is a magnetic force on a particle. It is possible that the particle is:

An electron is released such that its initial velocity is from right to left across this page. The electron's path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field. What is the direction of this field?

A proton moving at a speed of 3.8 *106 m/s cuts across the lines of a magnetic field at an angle of 40°. The strength of the field is 0.25 *10-4 T. What is the magnitude of the force acting on the proton? (qp = 1.6 *10-19 C)

A stationary positive charge +Q is located in a magnetic field B, which is directed toward the right as indicated. The direction of the magnetic force on Q is:

Assume that a uniform magnetic field is directed into this page. If a proton is released with an initial velocity directed from the bottom edge to the top edge of the page, which of the following describes the direction of the resultant force acting on the proton?

A proton moving with a speed of 6.0 *105 m/s perpendicular to a uniform magnetic field of 0.20 T will follow which of the paths described below? (qp = 1.6 *10-19 C and mp = 1.67 * 10-27 kg)

The right-hand rule allows one to find a property of the interaction of a magnetic field with a charged particle. The right-hand rule applied to moving charges:

The path of a charged particle moving perpendicular to a uniform magnetic field will be a:

A deuteron, with the same charge but twice the mass of a proton, moves with a speed of 6.0 * 10⁵m/s perpendicular to a uniform magnetic field of 0.20 T. Which of the paths described below would it follow? (q_p = 1.6 * 10 ^- ¹⁹ C and m_d = 3.34 *10 ^- ²⁷ kg)

Two singly ionized isotopes, X and Y, of the same element move with the same speed perpendicular to a uniform magnetic field. Isotope X follows a path of radius 3.35 cm while isotope Y moves along a path 3.43 cm in radius. What is the ratio of the two isotope masses, m_Y/m_X?

A proton, which moves perpendicular to a magnetic field of 0.60 T in a circular path of radius 0.080 m, has what speed? (q_p = 1.6 10^-¹⁹ C and m_p = 1.67 10^-²⁷ kg)

An electron which moves with a speed of 7.5 10³ m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 10^-¹⁹ C)

A proton moving at a speed of 3.8 10⁶ m/s cuts across the lines of a magnetic field at an angle of 40°. The strength of the field is 0.25 10^-⁴ T. What is the magnitude of the force acting on the proton? (q_p = 1.6 *10^-¹⁹ C)

A proton moving with a speed of 6.0 10⁵ m/s perpendicular to a uniform magnetic field of 0.20 T will follow which of the paths described below? (q_p = 1.6 10^-¹⁹ C and m_p = 1.67 * 10^-²⁷ kg)