1)
Which of the following situations is not true for magnets?
Like poles repel each other.
Unlike poles repel each other.
North poles repel each other.
A north pole and a south pole will attract each other.
2)
Where is the magnitude of the magnetic field around a permanent magnet greatest?
The magnitude is greatest close to the poles.
The magnitude is greatest far from the poles.
The magnitude is equal at all points on the field.
The magnitude is greatest halfway between poles.
3)
One useful way to model magnetic field strength is to define a quantity called magnetic flux . Which of the following definitions for magnetic flux, , is correct?
the number of field lines that cross a certain area
(surface area) x (magnetic field component normal to the plane of surface)
all of the above
4)
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 ____ magnetism.
domain; no
pole; some
cell; unusual
ion; strong
5)
Which statement describes Earth's magnetic declination?
the angle between Earth's magnetic field and Earth's surface
Earth's magnetic field strength at the equator
the tendency for Earth's field to reverse itself
the angle between true north and north indicated by a compass
6)
A current in a long, straight wire produces a magnetic field. These magnetic field lines
radiate out from the wire to infinity.
come in from infinity to the wire.
form circles that pass through the wire.
form circles that go around the wire.
7)
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 force, Fmagnetic.
the magnetic field, B.
the current's velocity, v.
the current's path, P.
8)
Under which of the following conditions is the net magnetic force on a charged particle equal to zero?
when the particle is stationary
when the particle is moving parallel to the magnetic field
when the particle is not charged
all of the above
9)
An electron moves north at a velocity of 4.5 x 104 m/s and has a magnetic force of 7.2 x 10-18 N exerted on it. If the magnetic field points upward, what is the magnitude of the magnetic field?
1.0 mT
2.0 mT
3.6 mT
4.8 mT
10)
The direction of the force on a current-carrying wire in an external magnetic field is
perpendicular to the current only.
perpendicular to the magnetic field only.
perpendicular to both the current and the magnetic field.
parallel to the current and to the magnetic field.
11)
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.
north
south
east
west
12)
A current can be induced in a closed circuit without the use of a battery or an electrical power supply by moving the circuit through a
high temperature field.
gravitational field.
magnetic field.
nuclear field.
13)
A bar magnet falls through a loop of wire with constant velocity, and the north pole enters the loop first. The induced current will be greatest when the magnet is located so that the loop is
near either the north or the south pole.
near the north pole only.
near the middle of the magnet.
With no acceleration, the induced current is zero.
14)
A loop of wire is rotated 360° across an external magnetic field. During one period of revolution, the induced current changes in
magnitude only.
direction only.
both magnitude and direction.
amplitude.
15)
According to Lenz's law, the magnetic field of an induced current in a conductor will
enhance the applied field.
heat the conductor.
increase the potential difference.
oppose a change in the applied magnetic field.
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