 # Cutnell/Johnson Physics 8th edition Reading Quiz Questions

## Presentation on theme: "Cutnell/Johnson Physics 8th edition Reading Quiz Questions"— Presentation transcript:

Cutnell/Johnson Physics 8th edition Reading Quiz Questions
Classroom Response System Questions Chapter 21 Magnetic Forces and Magnetic Fields Reading Quiz Questions

21.1.1. How is the direction of a magnetic field at a location indicated?
a) A magnetic field is always directed toward due north. b) A magnetic field is always directed in the direction that the north pole of a small compass needle points at the location. c) A magnetic field is always directed directly opposite to the direction that the north pole of a small compass needle points at the location. d) A magnetic field is always directed perpendicular and vertically upward from the direction that the north pole of a small compass needle points at the location. e) A magnetic field is always directed perpendicular and vertically downward from the direction that the north pole of a small compass needle points at the location.

21.1.2. Which one of the following statements concerning permanent magnets is false?
a) Magnets can exert forces on each other. b) A north pole attracts a south pole. c) There is a magnetic field surrounding a magnet. d) The north pole of a compass points toward the south pole of a permanent magnet. e) The magnetic field is directed away from a north pole and into a south pole.

Complete the following sentence: When a positively-charged particle is released from rest in a region that has a magnetic field directed due east, the particle will a) remain at rest. b) be accelerated due east. c) be accelerated due north. d) be accelerated upward. e) be accelerated downward.

Complete the following sentence: When a negatively-charged particle is moving at a constant velocity due east and enters in a region that has a magnetic field directed due east, the particle will a) be accelerated due east. b) be accelerated due west. c) be accelerated upward. d) be accelerated downward. e) continue moving due east at constant velocity.

Which one of the following conditions is not a requirement for a particle to experience a magnetic force when placed in a magnetic field? a) The particle must be moving. b) The particle must be charged. c) The particle must not be under the influence of any other forces. d) The velocity of the particle must have a component that is perpendicular to the direction of the magnetic field.

21.2.4. What is Right-Hand Rule #1 used to determine?
a) Given the directions of the magnetic field and the velocity of a charged particle, it is used to find the direction of the magnetic force on the particle. b) Given the directions of the magnetic field and magnetic force on a charged particle, it is used to determine the magnitude and sign of charge on the particle. c) Given the magnitude and sign of the charge on a particle and the direction of the magnetic force, it is used to determine the net force on the particle. d) It is used to determine the direction of the “reaction force” when applying Newton’s third law of motion to the particle.

21.2.5. Which one of the following is the SI unit for the magnetic field?
a) monopole (MP) b) tesla (T) c) fermi (Fm) d) gross (G) e) Oersted (oe)

Consider the following quantities: (1) mass, (2) velocity, (3) charge, and (4) magnetic field strength. Upon which of these quantities is the force on a charged particle moving in a magnetic field dependent? a) 1 and 4 only b) 2 and 3 only c) 1, 3, and 4 only d) 2, 3, and 4 only e) 1, 2, and 3 only

21. 2. 7. A charged particle is moving in a magnetic field
A charged particle is moving in a magnetic field. What is the direction of the force on the particle due to the magnetic field? a) in the direction of the magnetic field b) in the direction opposite to which the particle is moving c) in the direction that is perpendicular to both the magnetic field and the velocity d) in the same plane as the magnetic field and the velocity, but not in either of those two directions e) in the direction of motion

An electron is traveling due south when it enters a uniform magnetic field directed due west. Which of the following statements concerning this situation is false? a) The subsequent motion of the electron will be the same as if there were an electric field directed due west and no magnetic field present. b) The electron will follow a curved path. c) The direction of the magnetic force on the electron will vary with time. d) The magnitude of the magnetic force will be constant with time. e) The direction of the magnetic field and the direction of the magnetic force on the electron are perpendicular to one another.

21.3.2. What is the use of a bubble chamber?
a) to accelerate charged particles before they move into a magnetic field b) to allow the trajectory of charged particles moving in a magnetic field to be observed and measured c) to make a magnetic field within a region of space uniform d) to increase the mass of charged particles so that their trajectories are more easily observed e) to charge a neutral particle or the increase the charge on a particle before it enters a magnetic field

In a mass spectrometer, a charged particle is initially accelerated using a potential difference before it enters a magnetic field. According to the textbook, how is a mass spectrometer used to determine the mass of a charged particle? a) The speed of each particle is measured as it enters the detector. b) The radius of each particle is measured as it moves through a uniform magnetic field with a constant magnitude and direction. c) The magnitude of the potential difference is adjusted until the particle follows a curve with a particular radius so that it enters a detector. d) The acceleration of the particle is measured as it moves through a uniform magnetic field with constant magnitude and direction. e) The magnetic field is varied until the particle moves along a curve with a particular radius so that it enters a detector.

A negatively-charged particle is slowly moving as it enters a region that has a constant magnetic field. If the velocity of the particle is initially perpendicular to the magnetic field, what will be the subsequent motion of the particle? a) It will follow a helical path around the magnetic field lines. b) It will follow a circular path in the plane perpendicular to the magnetic field lines. c) It will follow a straight line path in the same direction as it was initially traveling. d) It will follow a circular path in a plane parallel to the magnetic field lines. e) It is impossible to predict the path the particle will follow.

A negatively-charged particle is slowly moving as it enters a region that has a constant magnetic field. If the velocity of the particle is initially parallel to the magnetic field, what will be the subsequent motion of the particle? a) It will follow a helical path around the magnetic field lines. b) It will follow a circular path in the plane perpendicular to the magnetic field lines. c) It will follow a straight line path in the same direction as it was initially traveling. d) It will follow a circular path in a plane parallel to the magnetic field lines. e) It is impossible to predict the path the particle will follow.

Which one of the following parameters is not used to determine the magnetic force on a current-carrying wire in a magnetic field? a) length of the wire b) radius of the wire c) direction of the magnetic field with respect to the direction of the current d) the strength of the magnetic field e) the magnitude of the electric current

There are many devices that utilize the effects of a magnetic field on a current carrying wire. Which one of the following devices does not rely on these effects for its operation? a) an electric motor b) a loudspeaker c) an electric toaster d) a magnetohydrodynamic (MHD) ship

A long wire carries a current toward the north in a magnetic field that is directed vertically downward. What is the direction of the magnetic force on the wire? a) west b) north c) east d) vertically upward e) vertically downward

A long wire carries a current toward the east in a magnetic field that is directed due south. What is the direction of the magnetic force on the wire? a) west b) north c) east d) vertically upward e) vertically downward

21. 6. 1. A constant direct current is passing through a loop of wire
A constant direct current is passing through a loop of wire. The loop is free to rotate about an axis that is parallel to and passes through the plane of the loop. Under what circumstance is the maximum torque produced on the loop by the magnetic force? a) The area of the loop is reduced to one-half of its initial value. b) The magnetic field is oriented parallel to the plane of the loop. c) The current is reduced to one-half of its initial value. d) The magnetic field is oriented perpendicular to the plane of the loop. e) The magnetic field is reduced to one-half of its initial value.

21.6.2. Which one of the following choices is not an essential part of an electric motor?
a) Josephson junction b) magnets c) wire coil d) split-ring commutator e) a battery

21. 7. 1. A magnetic field is generated by a current-carrying wire
A magnetic field is generated by a current-carrying wire. Which one of the following statements concerning this situation is false? a) The magnitude of this magnetic field decreases with increasing distance away from the wire. b) Right-hand Rule No. 2 is useful for determining the direction of the magnetic field at a particular location. c) The magnitude of the magnetic field is directly proportional to the magnitude of the current. d) The magnetic field is parallel to the direction of the current in the wire.

21. 7. 2. Two long wires are parallel to each other
Two long wires are parallel to each other. One wire carries a current directed due east and the other carries a current of the same magnitude, but directed due west. Which one of the following statements concerning this situation is false? a) The magnetic field in the plane of the wires at the midpoint between the two wires is equal to zero tesla. b) The magnetic forces due to the currents carried by the wires causes the wires to move apart. c) If you are looking toward the west along the wire carrying the current toward the west, the magnetic field lines are directed clockwise around the wire. d) The magnetic field produced by each wire has its greatest magnitude outside, but near the surface of the wire.

What is a solenoid? a) a single loop of wire in the shape of a circle b) a radio antenna c) a long coil of wire in the shape of a helix d) a scanning mechanism inside of a television e) a magnet that is inserted into a coil of wire

21.7.4. Which one of the following choices is not a possible way to produce a magnetic field?
a) Set up a current in a long, straight wire. b) Uniformly distribute charges over the surface of a conductor. c) Make an object out of materials that have an intrinsic magnetic field. d) Pass a current through a coil of wire.

Which one of the following choices correctly indicates the proportionality between magnetic field due to a current carrying, long straight wire and the distance R from the wire? a) b) c) d) e)

Consider two parallel wires carrying current in the same direction. Which one of the following statements to true concerning this situation? a) The two wires will attract each other, even if no external magnetic field is applied to the wires. b) The two wires will repel each other, even if no external magnetic field is applied to the wires. c) The two wires will attract each other, only if an external magnetic field is applied to the wires. d) The two wires will repel each other, only if an external magnetic field is applied to the wires. e) The wires will be neither attracted nor repelled from each other when no external magnetic field is applied to the wires.

Consider two parallel wires carrying current in opposite directions. Which one of the following statements to true concerning this situation? a) The two wires will attract each other, even if no external magnetic field is applied to the wires. b) The two wires will repel each other, even if no external magnetic field is applied to the wires. c) The two wires will attract each other, only if an external magnetic field is applied to the wires. d) The two wires will repel each other, only if an external magnetic field is applied to the wires. e) The wires will be neither attracted nor repelled from each other when no external magnetic field is applied to the wires.

Which one of the following statement concerning Ampere’s law for static magnetic fields is false? a) The strength of the magnetic field produced by the current is not dependent on the distance from the current geometry that produces the magnetic field. b) A closed path of arbitrary shape is constructed around the current. c) This law may be applied to any current geometry that produces a magnetic field that does not change with time. d) The component of the magnetic field that is parallel to the closed path is used in Ampere’s law. e) The permeability of free space is a constant that appears in Ampere’s law.

21.8.2. Which of the following may be determined using Ampere’s law?
a) electric fields due to current carrying wires b) magnetic forces between two current carrying wires c) magnetic fields due to current carrying wires d) magnetic forces acting on charged particles e) magnetic fields due to permanent magnets

21.9.1. Which one of the following materials is not ferromagnetic?
a) cobalt b) nickel c) chromium dioxide d) iron e) aluminum

21.9.2. What produces the magnetism of an individual atom?
a) the nuclear force that holds protons within the atomic nucleus b) the orbital and spin motions of electrons c) the motion of the atom itself d) the electric interaction between electrons and protons e) neutrons are naturally magnetic