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Unformatted text preview: Physics Discretes
Time: 30 Minutes
Number of Questions: 30 This
questions—questions that are NOT based on a
descriptive passage. These discretes comprise
15 of the 77 questions on the Physical
Sciences and Biological Sciences sections of
the MCAT. MCAT PHYSICS DISCRETES TEST
DIRECTIONS: The following questions are not
based on a descriptive passage; you must select
the best answer to these questions. If you are
unsure of the best answer, eliminate the choices
that you know are incorrect, then select an
answer from the choices that remain. Indicate
your selection by blackening the corresponding
circle on your answer sheet. A periodic table is
provided below for your use with the questions. PERIODIC TABLE OF THE ELEMENTS
(267) * 58
175.0 † 90
(260) GO ON TO THE NEXT PAGE. 2 as developed by Physics Discretes Test 1 . An ideal
experiences: gas compressed adiabatically A . a decrease in temperature and an increase
B . a decrease in temperature and a decrease
C . an increase in temperature and an increase
D . no change in either the temperature
internal energy. in
in 4 . An object is moving counterclockwise in a circle
at constant speed. Which of the following
diagrams correctly indicates both its velocity
vector and its acceleration vector?
v 2 . Two identical rods having temperatures 100°C
and 50°C, respectively, are brought into contact.
If the system is isolated from the environment,
its entropy: 3 a
v a B. A.
D. C. v increases.
remains the same.
cannot be determined. ar D. v
a 5 . An ambulance originally at rest has its siren
going. The ambulance starts accelerating away
from a boy standing nearby. He will hear:
D. a decrease in the pitch of the siren.
no change in the pitch of the siren.
an increase in the pitch of the siren.
an increase, and then a decrease in the pitch
of the siren. A 1.0 kg object moving east with a velocity of
10 m/s has a head-on collision with a 0.5 kg
object which is at rest. Neglecting friction, what
is the momentum of the system after collision?
D. 15 kg • m/s; east
15 kg • m/s; west
10 kg • m/s; east
10 kg • m/s; west GO ON TO THE NEXT PAGE. KAPLAN 3 6 . The diagram shows energy levels E1, E 2, E 3, and
E4 in an atom. If the transition from energy E3
to E2 gives rise to a photon of radiation of a
particular wavelength, which of the following
transitions could give rise to a photon of
radiation of longer wavelength? 9 . An object (O) is placed within the focal length f
of a converging lens. The image (I) is located at
which of the following positions?
f E4 f' Energy (eV) E3 I I B. O E2 f
f' E1 A.
D. E 4 to E1
E 3 to E1
E 2 to El
E 4 to E3 f
O f f' 7 . The activity of a radioactive source falls to onesixteenth of its original value in 32 minutes.
What is the half-life, in minutes, of this decay
min I 1 0 . When the 2/3 Ω resistor is replaced by an 8/3 Ω
resistor, the voltage across the resistor changes
9V 8 . A parallel plate air capacitor is connected across a
battery of constant emf. If the separation of the
plates is decreased, which of the following
I. Charge on the plates of the capacitor
II. Potential difference between the plates
of the capacitor
III. Capacitance of the capacitor
D. III only
I and II only
I and III only
II and III only 2/3 Ω
V. Physics Discretes Test 1 1 . From the data shown below, estimate the halflife of element X. Number of Undecayed Nucleii 10 x 105 1 3 . In the diagram below a stream of electrons leaves
the electron gun at G and strikes the fluorescent
screen at P. When the current is switched on at
S, it flows through the wire coils in an
anticlockwise direction as seen by the observer at
O; the observer sees the spot of light at P: Element X
7.5 x 105 G 5 x 105 P O 2.5 x 105 0 1.5 3.0 4.5 6.0 S Years elapsed A.
D. 1.5 years
6.0 years 1 2 . A planet has a diameter one half of the Earth’s
diameter and a mass that is one half of the
Earth’s mass. What would be the acceleration due
to gravity on the planet?
D. 2.45 m/s2
19.6 m/s2 A.
D. move downwards.
move to the left.
move to the right.
remain still. 1 4 . Object A of mass M is released from height H
while object B of mass 0.5 M is released from
height 2H. What is the ratio of the velocity of
object A to the velocity of object B immediately
before they hit the ground? (Note: Assume that
air resistance is negligible.)
1:4 GO ON TO THE NEXT PAGE. KAPLAN 5 1 5 . In the hydraulic lift shown below, piston A has a
cross-sectional diameter of 2 m and piston B a
cross-sectional diameter of 4 m. If the force
exerted by piston A on the liquid is doubled, the
force lifting up piston B is: A A.
D. B 1 7 . A fluid flows through a pipe such that the
velocity at point A is 1/4 that at point B. What
is the ratio of the radius of the pipe at point A to
that at point B?
1:2 1 8 . A cube of wood whose sides are each 10 cm
weighs 16 N in air. When half submerged in an
unknown liquid it weighs only 10 N. What is the
density of the liquid? (Note: Assume g = 10
m/s2.) decreased by a factor of 4.
increased by a factor of 2.
increased by a factor of 4.
increased by a factor of 8. A . 600 kg/m3
C . 1,000 kg/m3
D . 1,200 kg/m3 1 6 . Which of the following is true of the adiabatic
expansion from point Q to R? P T Q
S R 1 9 . Two fixed charges of +Q and +3Q repel each
other with a force, F. If an additional charge of
–2Q is now added to each of the two charges,
what is the new force between them?
F/3 attraction V
A . The internal energy at Q is greater than at R.
B . The internal energy at R is greater than at Q.
C . Heat is released by the gas in moving from
Q to R.
D . Heat is absorbed by the gas in moving from
Q to R. 2 0 . If the binding energy of a nucleus is 186.2 MeV,
what is its mass defect? (Note: 1 amu yields 931
MeV of energy, 1 amu is equivalent to 1.66 ×
kg Physics Discretes Test 2 1 . A block starts from rest and slides down along
one quadrant of a frictionless circular track whose
radius is one meter. Which of the following is
true? 2 4 . In a frictionless horizontal mass spring system,
as the mass moves from the point of maximum
expansion through the equilibrium position to
the point of maximum compression, the
potential energy of the system:
A . The speed of the block at the bottom will be
the same as if it had fallen vertically.
B . Mechanical energy will not be conserved.
C . The acceleration of the block is constant
throughout the descent.
D . The total work done by gravity is greater
than if the block had fallen vertically. decreases continually .
increases then decreases.
decreases then increases.
remains the same. 2 5 . Which of the following diagrams accurately
depicts the electric field lines between 2 charges
of equal magnitude but opposite sign?
A. C. B. D. 2 2 . Which one of the following is a scalar quantity?
Kinetic energy 2 3 . A fireboat is fighting a fire to its right but also
has its hoses going full blast into the water to its
left. Which law of physics best explains the
reason for this?
D. Newton’s law of gravity
Newton’s second law
Newton’s third hew
Conservation of energy GO ON TO THE NEXT PAGE. KAPLAN 7 MCAT 2 6 . Four positively charged spheres (+1 C each) and
four negatively charged spheres (–1 C each) are
distributed at equally spaced intervals around a
circular hoop whose radius is 1 m as shown
below. What is the electrostatic potential at the
center of the hoop? (Note: k is the electrostatic
constant.) 2 8 . In an attempt to restore the natural rhythm of a
heart attack victim, electric shock plates are
sometimes used. The shock plates are run off a
10 V battery and draw current at a constant 30 A.
If each shock draws 300 J of electrical energy,
what is the duration of the shock?
+ + + – – –
– 2 9 . A bat locates obstacles in its flight path by
emitting sound in the same direction as it travels.
When the sound encounters an obstacle, it is
reflected back to the bat. Assuming that the bat’s
velocity and the frequency of the emitted sound
are constant, and assuming the obstacle is
stationary, which of the following describes the
frequency observed by the bat?
A . It is greater than the frequency emitted by the
B . It is less than the frequency emitted by the
C . It is the same as the frequency emitted by the
D . Its character cannot be determined. A. 0V
B . 4k V
C . 8k V
D . 16k V 2 7 . Which of the following quantities can be
expressed dimensionally as M • L2/T2, where M
is mass, L is length, and T is time? 0.1 sec
3.0 sec 3 0 . An object is moved from 2f towards f, where f is
the focal length of this converging lens. The
image formed on the other side of the lens will
move from: I. Torque
D. I only
I and II only
II and III only
I, II, and III 2f f A.
D. f f to 2f.
2f to f/2.
2f to f.
2f to infinity.
END OF TEST 2f ...
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This note was uploaded on 06/21/2009 for the course SSD 34 taught by Professor Dfdedf during the Spring '09 term at Abraham Baldwin Agricultural College.
- Spring '09