Physics Chapter 19

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

form circles that go around the wire.

The lines of the magnetic field around a current-carrying wire

form concentric circles around the wire.

Find the direction of the force on an electron moving through the magnetic field shown above. (relative to the page)

in

From a front view, find the direction of the magnetic force just off to the left side on a vertical wire carrying a downward current. (show the diagram)

in

In a magnetized substance, the domains

line up mainly in one direction.

A solenoid is in an upright position on a table. A clockwise current of electrons—when viewed from above—causes the solenoid to have a ____ magnetic pole at its bottom end. If a compass is placed at the top of the solenoid, the north pole of the compass would be ____.

north; attracted

The direction of the force on a current-carrying wire in an external magnetic field is

perpendicular to both the current and the magnetic field.

A current-carrying conductor has a current that is moving perpendicular to a magnetic field which experiences a force that is

perpendicular to the current.

A horizontally left to right clockwise wound coil has a battery connected to the coil. The battery sits directly under the coil and has the current flowing out the battery to the left. Determine the magetic field direction on the right hand side of the coil.

right

In domain alignment persists after the external magnetic field is removed.

The material returns to an unmagnetized state.

A stationary positive charge, Q, is located in a magnetic field, B, which is directed toward the right. What is the direction of the magnetic force on Q?

There is no magnetic force.

Which of the following situations is not true for magnets?

Unlike poles repel each other.

Which compass needle orientation in the figure above might correctly describe the magnet's field at that point?

a

All of the following statements about magnetic field lines around a permanent magnet are true except which one?

Magnetic field lines appear to end at the north pole of a magnet.

Which of the following statements about Earth's magnetic field is true?

The geographic South Pole of Earth and Earth's magnetic north pole are relatively close to each other.

Where is the magnitude of the magnetic field around a permanent magnet greatest?

The magnitude is greatest close to the poles.

One useful way to model magnetic field strength is to define a quantity called magnetic flux Φ M . Which of the following definitions for magnetic flux, Φ M , is correct?

all of the above

Under which of the following conditions is the net magnetic force on a charged particle equal to zero?

all of the above

When an iron rod is inserted into a solenoid coil's center, the magnetic field produced by the current in the loops

causes alignment of the domains in the iron.

What is the path of an electron moving perpendicular to a uniform magnetic field?

circle

Which of the following modifications to a solenoid would be most likely to decrease the strength of its magnetic field?

decreasing the current and reducing the number of coils

In a permanent magnet,

domain alignment persists after the external magnetic field is removed.

A microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction is called a(n) ____. In most materials, when these groups are randomly distributed, the substance will show ____ no magnetism.

domain; no

An electron moves into a region of the magnetic field. Which arrow represents the direction this electron would travel?

down arrow

If a proton is released at the equator and falls toward Earth under the influence of gravity, the magnetic force on the proton will be toward the ____ assuming the magnetic field is directed toward the north at this location.

east

A solenoid is in an upright position on a table. A counterclockwise current of electrons—when viewed from above—causes the solenoid to have a ____ magnetic pole at its bottom end. If a compass is placed at the top of the solenoid, the north pole of the compass would be ____.

south; repelled

What is the path of an electron moving parallel to a uniform magnetic field?

straight line

Which statement describes Earth' s magnetic declination?

the angle between true north and north indicated by a compass

According to the right-hand rule, if a current-carrying wire is grasped in the right hand with the thumb in the direction of the current, the four fingers will curl in the direction of

the magnetic field, B.

Consider two long, straight, parallel wires, each carrying a current I. If the currents move in the same direction,

the two wires will attract each other.

Consider two long, straight, parallel wires, each carrying a current I. If the currents move in opposite directions,

the two wires will repel each other.

Find the direction of the force on a proton moving through the magnetic field shown above. (relative to the page)

up