Current that is typically 60 hertz is
A) direct current.
B) alternating current.
C) either of these
D) neither of these
Answer:
In an electrically neutral atom the number of protons in the nucleus is equal to the
number of
A) electrons that surround the nucleus.
B) neutrons in the nucleus.
C) both electrons and neutrons.
D) none of the above
Answer:
Which will leak more neutrons?
A) two separate lumps of uranium.
B) the same two lumps stuck together.
C) both the same
Answer:
When an iron ring is heated, the hole becomes
A) smaller.
B) larger.
C) neither smaller nor larger.
D) either smaller or larger, depending on the ring thickness.
Answer:
The air in your classroom has
A) mass.
B) weight.
C) energy.
D) all of the above
E) none of the above
Answer:
A tree stump is pulled northward by a 10-N force at the same time a 25-N force pulls it
southward. The resultant force has a magnitude of
A) 0 N.
B) 15 N.
C) 25 N.
D) 150 N.
Answer:
What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz?
A) less than 1 km
B) 1 km
C) more than 1 km
Answer:
Which best shields you from sunburn when at the beach?
A) a cloudy day
B) a sheet of glass between you and the Sun
C) frequent turning of your body
D) all of the above
E) none of the above
Answer:
A turbogenerator produces
A) energy.
B) power.
C) neither, but transforms energy from one form to another.
D) none of the above
Answer:
The electrical force between charges is strongest when the charges are
A) close together.
B) far apart.
C) either of these
D) need more information
Answer:
The voltage across the input terminals of a transformer is 120 V. The primary has 25
loops and the secondary has 50 loops. The voltage the transformer delivers is
A) 30 V.
B) 60 V.
C) 120 V.
D) 240 V.
E) none of the above
Answer:
When a barrel of water in a rowboat in a swimming pool is poured overboard, the pool
level
A) rises.
B) falls.
C) remains unchanged.
Answer:
When a boxer moves into an oncoming punch, the force experienced is
A) decreased.
B) increased.
C) no different, but the timing is different.
D) all of the above
Answer:
Nuclei of atoms that make up a newborn baby were manufactured in
A) the mother’s womb.
B) the food the mother eats before delivery.
C) ancient stars.
D) the Earth.
E) none of the above
Answer:
A transformer actually transforms
A) voltage.
B) magnetic field lines.
C) generators into motors.
D) non-safe forms of energy to safe forms of energy.
E) all of the above
Answer:
Secondary wavelets spread from a wave with
A) reduced speed.
B) an unchanging speed.
C) an increased speed.
D) none of the above
Answer:
Compared to the ocean, Earth’s atmosphere is different in that
A) its density varies with depth.
B) it has a less-distinct surface.
C) molecules are more greatly spaced.
D) all of the above
E) none of the above
Answer:
When voltage is stepped up in a transformer, current is stepped down. But Ohm’s law
tells us that greater voltage means greater current, not less current. How then can
current be lower when voltage is increased?
A) Current in the secondary is lower when compared to the greater current drawn by the
primary.
B) Ohm’s law applies to the circuit connected to the secondary, not to the transformer.
C) both of these
D) neither of these
Answer:
A heater draws 20A when connected to a 110-V line. If the electric power costs 20 cents
per kilowatt hour, the cost of running the heater for 10 hours is
A) $0.44.
B) $1.10.
C) $4.40.
D) $11.00.
E) none of the above
Answer:
The finding that electrons in an atom occupy a volume much greater than the volume of
the nucleus is best explained by
A) electromagnetic forces.
B) angular momentum conservation.
C) relative sizes of electrons and nuclei.
D) the wave nature of the electron.
E) none of the above
Answer:
The primary purpose of a lightning rod is to
A) attract lightning and guide it to the ground.
B) discharge the structure to which it is attached.
C) cancel the electric field within the structure to which it is attached.
D) induce a charge opposite to that of charged clouds overhead.
Answer:
As the polar icecaps melt, the resulting water spreads over the entire Earth. This new
mass distribution tends to make the length of a day
A) longer.
B) shorter.
C) none of these
Answer:
Which of the following is not a vector quantity?
A) velocity
B) speed
C) acceleration
D) all are vector quantities
E) none are vector quantities.
Answer:
Which horse moves faster in m/s on a merry-go-round?
A) one near inner rail
B) one near outer rail
C) both move at the same speed in m/s.
Answer:
The energy of sound in air eventually becomes
A) increased internal energy in the air.
B) weaker and weaker until it disappears.
C) cancelled by destructive interference.
D) all of the above
E) none of the above
Answer:
When a mirror with a fixed beam on it is rotated through a certain angle, the reflected
beam is rotated through an angle that is
A) equal to the angle of rotation.
B) twice as large.
C) four times as large.
D) none of these
Answer:
If Earth’s mass decreased to one-half its original mass with no change in radius, then
your weight would
A) decrease to one-quarter.
B) decrease to half.
C) stay the same.
D) none of the above
Answer:
A device that transforms electrical energy to mechanical energy is a
A) generator.
B) motor.
C) transformer.
D) magnet.
E) none of the above
Answer:
The buoyant force on a one-ton blimp hovering in air is
A) zero.
B) one ton.
C) less than one ton.
D) more than one ton.
Answer:
Freddy Frog drops vertically from a tree onto a horizontally-moving skateboard. The
reason he doesn’t slip off the skateboard is due to
A) inertia in motion.
B) momentum change.
C) friction between his feet and the board.
Answer:
Nellie tosses a ball upward at an angle. Neglecting air resistance, the vertical
component of the initial velocity
A) decreases with time to reach the top.
B) remains constant.
C) increases with time to reach the top.
Answer:
The amount of current produced by electromagnetic induction depends on the
A) amount of induced voltage.
B) resistance of the circuit to which it is connected.
C) both of these
D) neither of these
Answer:
The current drawn by a 1200-W toaster connected to 120 V is 10 A. The resistance of
the toaster coils is
A) 6 ohms.
B) 12 ohms.
C) 18 ohms.
D) none of the above
Answer:
If the pencil you are holding were 10 times as long and 10 times as wide, its surface
area would be multiplied by
1) 10
2) 100
3) 1000
4) 10,000
5) none of these
and its volume would be multiplied by
6) 10.
7) 100.
8) 1000.
9) 10,000.
10)none of these.
Answer:
When steam condenses, the H2O
1) releases energy.
2) absorbs energy.
3) neither of these.
When water freezes, the H2O
4) releases energy.
5) absorbs energy.
6) neither of these.
Answer:
Figure A-2
If the mass per nucleon in atomic nuclei varied as shown in the fictitious plot above,
then nuclear energy would be available from the element iron (atomic no. 26 by the
process of nuclear
1) fission.
2) fusion.
3) both.
4) neither.
Accordingly, uranium would yield energy by nuclear
5) fission.
6) fusion.
7) both.
8) neither.
Answer:
A radioactive isotope has a half-life of one week. At the end of two weeks the amount
remaining is
1) none,
2) one-eighth,
3) one-quarter,
4) one-half,
and at the end of three weeks the amount remaining is
5) none.
6) one-eighth.
7) one-quarter.
8) one-half.
Answer:
When air rapidly expands, its temperature will
1) decrease,
2) increase,
3) stay the same,
whereas when air is rapidly compressed, its temperature will
4) decrease.
5) increase.
6) stay the same.
Answer:
When gas in a container is squeezed to half its volume, its density is
1) halved,
2) unchanged,
3) doubled,
4) quadrupled,
and neglecting any temperature changes we would find the gas pressure to be
5) halved.
6) unchanged.
7) doubled.
8) quadrupled.
Answer:
Figure N-7
Ball A is dropped from rest as ball B is shot out horizontally. Ball A hits the ground
1) before ball B.
2) after ball B.
3) at the same time as ball B.
This is because
4) ball A has less distance to travel.
5) ball B is acted upon by an additional force.
6) both balls fall the same vertical distance with the same acceleration.
Answer:
E.
Answer:
Figure V-7
The boat to make the fastest progress in its forward direction is boat
1) 1.
2) 2.
3) 3.
4) 4.
Boat 3 is not propelled in a forward direction because
5) the wind does not make impact with the sail.
6) there is no component of force parallel to the keel.
7) of air resistance on the front of the sail.
8) But it is propelled in a forward direction!
Answer:
A 100-newton sack of potatoes falls from an airplane. As velocity of fall increases, air
resistance also increases, and when air resistance equals 100 N, the acceleration of the
sack is
1) zero
2) 5 m/s2
3) 10 m/s2
4) 100 m/s2
and the velocity of the sack will be
5) 0 m/s.
6) 5 m/s.
7) 10 m/s.
8) 100 m/s.
9) constant.
Answer:
Figure V-4
Which of the sailboats shown sails the fastest in its forward direction?
1) 1
2) 2
3) 3
4) 4
It is interesting to note that
5) this is the only boat that sails forward.
6) only two of the boats sail forward.
7) three out of the four boats sail forward.
8) all sail forward, but at different speeds.
Answer:
If the handle of a tuning fork is held solidly against a table, its resulting sound is
1) louder,
2) softer,
3) doesn’t change,
and as a result of this, the length of time the fork keeps vibrating
4) increases.
5) decreases.
6) doesn’t change.
Answer:
When water at 4oC is heated, it expands. When water at 4oC is cooled, it
1) contracts,
2) expands,
3) neither contracts nor expands,
4) not enough information given,
which follows from the fact that
5) cooling decreases the kinetic energy of H2O molecules.
6) water has its greatest density at 4oC.
7) we do not know how the water is cooled.
Answer:
If an object is thrown downward from a tall cliff, its acceleration while falling (in the
absence of air resistance) will be
1) less than 10 m/s2.
2) 10 m/s2.
3) greater than 10 m/s2.
This is evident from the fact that
4) gravitational force depends upon the state of motion of an object.
5) each successive second the speed of the object increases by an additional 10 m/s.
6) the object was not simply dropped but thrown, therefore having an initial
acceleration of fall greater than zero.
Answer:
Escape speed from Earth is about
1) 8 km/s.
2) 11.2 km/s.
3) more than 11.2 km/s.
Interestingly, if a stone released at rest at the far edge of the solar system drops to Earth
by virtue of only Earth gravity, it will strike Earth’s surface with a speed of about
4) 8 m/s.
5) 10 km/s.
6) 11.2 km/s.
7) more than 11.2 km/s.
Answer:
The electrons that make up the current in an electric circuit move by
1) interacting with the electric field established in the circuit.
2) bumping into one another in such as way as to send pulses over long distances.
The drift speed of individual electrons making up the current is
3) very low, about a snail’s pace.
4) about the speed of sound.
5) about the speed of light.
Answer:
An object drops in free fall. At one instant it is moving at a speed of 50 meters per
second. Exactly one second later its speed is about
1) 10 m/s.
2) 50 m/s.
3) 60 m/s.
4) 100 m/s.
This is because
5) no net force acts on the object while in its state of free fall.
6) it gains a speed of about 10 m/s for each second of fall.
7) its velocity nearly doubles each second.
Answer:
Dew on the grass results from
1) fast-moving molecules.
2) evaporation.
3) open-structured water crystals.
4) the pressure of the atmosphere on water vapor.
5) the slowing down of fast-moving water molecules.
As dew forms on the grass, energy is
6) given to the grass by the water vapor.
7) given up by the grass to the water vapor.
Answer: