The voltage across the input terminals of a transformer is 120 V. The primary has 50
loops and the secondary has 25 loops. The voltage the transformer delivers is
A) 30 V.
B) 60 V.
C) 120 V.
D) 240 V.
E) none of the above
Clocks on a spaceship moving at high speed relative to the Earth run more slowly when
viewed from
A) within the spaceship.
B) Earth.
C) both of these
D) neither of these
The extraordinary blueness in lakes in the Canadian Rockies is the result of
A) high-altitude refraction of light.
B) glacial silt in the water scattering blue light.
C) the unique temperatures of these lakes throughout most of the year.
D) none of the above
If the mass of an object were doubled while its volume remained the same, its density
would
A) be half.
B) double.
C) stay the same.
D) be four times as great.
The identities of dark energy and dark matter are
A) unknown at this time.
B) subjects of intense astronomical interest.
C) both of these
D) neither of these
Which of these electromagnetic waves have the shortest wavelength?
A) radio waves
B) infrared waves
C) X-rays
D) ultraviolet waves
E) light waves
When a blinking light source moves relative to you, the speed of the light
A) changes but the frequency of blinks remains constant.
B) remains constant but the frequency of blinks can change.
C) stays the same, as does the blinking frequency.
A 10-meter-long spear is thrown at relativistic speeds through a 10-meter-long pipe.
(Both these dimensions are measured when each is at rest.) When the spear passes
through the pipe
A) the spear appears to shrink so the pipe completely covers it.
B) the pipe appears to shrink so the spear extends from both ends.
C) both appear to shrink equally so the pipe barely covers the spear.
D) any of these, depending on the motion of the observer (moving with the spear, at rest
with the pipe, and so on).
E) none of the above
Atoms can be photographed by
A) electron beams.
B) scanning electron microscopes.
C) both of these
D) neither of these
A postulate of special relativity is that the speed of light
A) like all motion, is relative.
B) for all observers is a constant.
C) both of these
D) neither of these
One neutron added to a helium nucleus results in
A) hydrogen.
B) boron.
C) lithium.
D) beryllium.
E) helium.
Burl and Paul have a total weight of 1300 N. The tensions in the supporting ropes that
support their scaffold add to 1700 N. The weight of the scaffold itself must be
A) 300 N.
B) 400 N.
C) 500 N.
D) 600 N.
An atomic model of the atom is
A) a symbolic representation of the atom.
B) a stepping stone to further understanding.
C) an abstraction enabling predictions.
D) all of the above
The strings in musical instruments that have greater mass tend to produce notes of
A) higher frequency.
B) lower frequency.
C) the same frequency.
D) none of the above
The principal advantage of ac power over dc power is that
A) more energy is dissipated during transmission.
B) ac voltage oscillates while dc voltage does not.
C) ac voltage can be transformed via conventional transformers.
D) ac circuits multiply power more easily.
E) ac circuits are safer.
The mass of ice that can be melted by 1 gram of 100oC steam is (Hint: Don’t forget
about hot water remaining from condensed steam.)
A) 0.125 gram.
B) 0.148 gram.
C) 6.75 grams.
D) 8 grams.
E) none of the above
The force of gravity acting on you will increase if you
A) burrow deep inside Earth.
B) stand on a planet with a shrinking radius.
C) both of these
D) neither of these
An astronaut traveling forward at 0.87c holds a meterstick in spear-like fashion. This
astronaut sees the spear’s length as
A) 0.5 m.
B) 0.87 m.
C) 1 m.
D) 1.25 m.
E) 1.5 m.
If a proton and an electron have the same momentum, the longer wavelength belongs to
the
A) proton.
B) electron.
C) both the same
The conservation of momentum is most closely related to
A) Newton’s 1st law.
B) Newton’s 2nd law.
C) Newton’s 3rd law.
D) Newton’s law of gravity
Fire a cannonball with enormous speed from a hypothetical cannon and it curves due to
gravity. Shine a light from a flashlight parallel to the cannon and it
A) follows a straight-line path.
B) curves downward as much as the cannonball.
C) curves slightly upward.
In optical fibers of uniform density, light actually
A) curves in a direction parallel to the central axis of the fiber.
B) travels in straight-line segments.
C) travels along the outer surface of the fiber.
D) none of the above
An 80-km/h airplane caught in a 60-km/h crosswind has a resultant speed of
A) 60 km/h.
B) 80 km/h.
C) 100 km/h.
D) 141 km/h.
When the handle of a tuning fork is held solidly against a table, the sound becomes
louder and the time that the fork keeps vibrating
A) becomes longer.
B) becomes shorter.
C) remains the same.
When a nucleus of U-238 absorbs a neutron and becomes U-239, a beta emission, then
another beta emission results in
A) Th-239.
B) Pa-239.
C) U-235.
D) Pu-239.
E) Pb-206.
If you measure the distance between two telephone poles with a steel tape on a very hot
day, your measured distance will be
A) a bit short.
B) a bit long.
C) the same as on an average-temperature day.
When a suction cup sticks to a wall it is
A) pulled to the wall by the vacuum.
B) pushed to the wall by the atmosphere.
C) both of these
D) neither of these
A rock is thrown vertically into the air. At the top of its path, its acceleration is
A) zero.
B) 10 m/s2.
C) between 0 and 10 m/s2.
D) greater than 10 m/s2.
Which is the smallest particle?
A) molecule
B) atom
C) proton
D) neutron
E) quark
A plasma differs from a gas in that
A) its molecules are farther apart.
B) it is hotter than a gas.
C) it is electrically conducting.
D) its atoms are boosted to higher atomic numbers.
E) all of the above