Physics 2 test 2

A person, standing on the ground, measures the earth's magnetic field to point in the direction shown in the figure. a) Which direction should the person walk to get to the geographic north pole? -To the left -To the right (b) Is the person standing in the northern or southern hemisphere? -Southern hemisphere -Northern hemisphere

(a) to the right (b) Southern Hemisphere

A charged particle is traveling through a uniform magnetic field. Which of the following statements are true of the magnetic field? (Select all that apply.) -It increases the kinetic energy of the particle. -It exerts a force on the particle that is parallel to the field. -It doesn't change the magnitude of the momentum of the particle. -It exerts a force that is perpendicular to the direction of motion. -It exerts a force on the particle along the direction of its motion.

-It doesn't change the magnitude of the momentum of the particle. -It exerts a force that is perpendicular to the direction of motion.

Which of the following statements is/are true? (Select all that apply.) -Magnetic field lines form complete loops. -Unlike electric field lines, magnetic field lines can cross each other. -Ferromagnetic materials can be magnetized more easily than other materials because their magnetic domains can be generally aligned. -Magnetic field lines exit the north pole of a magnet and reenter the south pole of a magnet.

-Magnetic field lines form complete loops. -Ferromagnetic materials can be magnetized more easily than other materials because their magnetic domains can be generally aligned. -Magnetic field lines exit the north pole of a magnet and reenter the south pole of a magnet.

Which of the following statements is true regarding an ammeter? A. Ammeters have a very high resistance and are placed in parallel with a resistor. B. Ammeters have a very low resistance and are placed in parallel with a resistor. C. Ammeters have a very high resistance and are placed in series with a resistor. D. Ammeters have a very low resistance and are placed in series with a resistor.

D. Ammeters have a very low resistance and are placed in series with a resistor.

Suppose you have three identical lightbulbs, some wire, and a battery. You connect one lightbulb to the battery and take note of its brightness. You add a second lightbulb, connecting it in parallel with the previous lightbulbs, again take note of the brightness. Repeat the process with the third lightbulb, connecting it in parallel with the other two. As the lightbulbs are added, how are the following properties affected? (Neglect the battery's internal resistance) brightness of the bulb individual currents in the bulb power delivered by the battery lifetime of the battery

remains unchanged remains unchanged increases decreases

Wire A has the same length and twice the radius of wire B. Both wires are made of the same material and carry the same current. Which of the following equations is true concerning the drift velocities vA and vB of electrons in the wires? vA = vB/4 vA = 4vB vA = vB vA = vB/2 vA = 2vB

vA = vB/4

A uniform magnetic field cannot exert a magnetic force on a particle in which of the following circumstances? (Select all that apply.) -The particle is charged. -The particle moves parallel to the field. -The particle is at rest. -The magnitude of the magnetic field changes with time. -The particle moves perpendicular to the field.

-The particle moves parallel to the field. -The particle is at rest.

Which of the following statements is/are true? (Select all that apply.) -Ferromagnetic materials are noticeably attracted to North and South poles of magnets. -Copper is noticeably attracted to North and South poles of magnets. -North poles are attracted to each other. -Magnetic monopoles have never been found in nature, and apparently do not exist. -South poles repel each other.

-ferromagnetic materials are noticeably attracted to North and South poles of magnets. -Magnetic monopoles have never been found in nature, and apparently do not exist. -South poles repel each other.

Two charged particles are projected into a region where a magnetic field is directed perpendicular to their velocities. If the charges are deflected in opposite directions, what are the possible relative charges and directions? (Select all that apply.) -oppositely charged, same initial direction -same charge, opposite initial direction -oppositely charged, opposite initial direction -same charge, same initial direction

-oppositely charged, same initial direction -same charge, opposite initial direction

How is a circuit breaker wired? A. in series with the device it is protecting B. in parallel with the device it is protecting C. neither in series or in parallel D. it is impossible to tell

A. in series with the device it is protecting

Suppose a current-carrying wire has a cross-sectional area that gradually becomes smaller along the wire, so that the wire has the shape of a very long, truncated cone. How does the drift speed vary along the wire? A. It slows down as the cross section becomes smaller. B. It speeds up as the cross section becomes smaller. C. It doesn't change. D. More information is needed.

B. It speeds up as the cross section becomes smaller.

Suppose an electrical wire is replaced with one having every linear dimension doubled (i.e., the length and radius have twice their original values). How is the resistance of the wire affected? A. The wire has more resistance than before. B. The wire has less resistance than before. C. The wire has the same resistance as before.

B. The wire has less resistance than before.

A bar magnet is placed in an external, uniform magnetic field as shown in the figure. Is there a resultant torque on the bar magnet, and if so, what is the direction of that torque? A. There is no torque. B. There is a clockwise torque. C. There is a counterclockwise torque.

B. There is a clockwise torque.

Which of the following statements is true regarding a voltmeter? A. Voltmeters have a very low resistance and are placed in series with a resistor. B. Voltmeters have a very high resistance and are placed in parallel with a resistor. C. Voltmeters have a very high resistance and are placed in series with a resistor. D.Voltmeters have a very low resistance and are placed in parallel with a resistor.

B. Voltmeters have a very high resistance and are placed in parallel with a resistor.

The north-pole end of a bar magnet is held near a stationary positively charged piece of plastic. How is the plastic affected? A. The plastic is attracted by the magnet. B. The plastic is repelled by the magnet. C. The plastic is unaffected by the magnet.

C. The plastic is unaffected by the magnet.

In the figure below the current is measured with the ammeter at the bottom of the circuit. When the switch is opened, the reading on the ammeter (increase/decrease)

decrease

Suppose you have three identical lightbulbs, some wire, and a battery. You connect one lightbulb to the battery and take note of its brightness. You add a second lightbulb, connecting it in series with the previous lightbulbs, again take note of the brightness. Repeat the process with the third lightbulb, connecting it in series with the other two. As the lightbulbs are added, how are the following properties affected? (Neglect the battery's internal resistance) brightness of the bulb individual currents in the bulb power delivered by the battery lifetime of the battery

decreases decreases decreases increases

In the figure below, the current is measured with the ammeter on the right side of the circuit diagram. When the switch is closed, the reading on the ammeter (increase, decrease)

increase