The Medical College - Page 39
80.
A glass viewport of area 65 cm
2 is located
near
the bottom of the tank at 70 meters below
the
surface. What is the force on the viewport
in
newtons?
A.
4110 N
C.
4460 N
B.
450 N
D.
5660 N
81.
If the sailor's total lung capacity is 6.3
liters and
he takes in this volume of air at the pressure
in the
air lock, to what approximate volume, in
liters,
will the air expand as he rises to the
surface
(where the absolute pressure is 1
atmosphere)?
A.
52 liters
C.
540 liters
B.
67 liters
D.
670 liters
82.
Because air contains 21% oxygen by
volume,
what is the partial pressure of oxygen in
the
lungs at the bottom of the 75 m escape
tank?
A.
2.12
10
4 N/m2 C.
1.76
10
5 N/m2
B.
1.57
10
5 N/m2 D.
1.01
10
6 N/m2
Passage IV (Questions 83–87)
A glass tube has a set of parallel metal plates
and is
evacuated of air. The plates are attached to a
battery of
100 volts. An electron, starting from rest at
the nega-
tive plate, accelerates uniformly toward the
positive
plate. At the same instant, a proton (which is
1835
times more massive than the electron) starts
from rest
at the positive plate and accelerates toward
the negative
plate. One can also apply a magnetic field
across the
region between the plates by the use of
externally
mounted current-carrying coils of
wire.
83.
Compare the kinetic energies in
electron-volts
of the proton and electron at the instant
each
reaches its opposite plate.
A.
proton: 183,500 eV and electron: 0.05
eV
B.
proton: 1 eV and electron: 183,500
eV
C.
proton: 100 eV and electron: 100
eV
D.
proton: 0.05 eV and electron: 100
eV
84.
Assume that the original accelerating
electric
field points horizontally north. A
horizontal
magnetic field pointing west is now
applied
using the external coils. What are the paths
of
the electron and proton now?
A.
They both travel in a straight line
without
deflecting.
B.
They are both deflected vertically
upward.
C.
The proton is deflected vertically
upward
and the electron downward.
D.
The proton is deflected to the west and
the
electron to the east.
85.
How does the magnetic field affect the speed
of
the electron and proton?
A.
The speeds of both are not
affected.
B.
The proton speeds up and the
electron
slows down.
C.
Both speed up due to the magnetic
force.
D.
The electron speeds up and the
proton
slows down.
86.
The magnetic coils are rotated so that the
mag-
netic field is now parallel to the electric
field
(north). What are the paths of the electron
and
proton now?
A.
They are both deflected upward.
B.
The proton deflects downward and
the
electron upward.
C.
Neither is deflected upward or
downward.
D.
The proton is deflected to east and
the
electron to west.
87.
The magnetic coils are turned off and an
addi-
tional small set of parallel plates is
mounted
horizontally to produce a vertically
upward
electric field. The proton and electron,
which
were traveling horizontally, enter the
region
where the upward E field exists. What
effect
does this field have on the paths of the
proton
and electron?
A.
No effect; they are not deflected.
B.
The proton is deflected upward and
the
electron downward.
C.
They are both deflected downward.
D.
The proton is deflected downward and
the
electron upward.
Questions 88–95 are independent of any
passage
and of each other.
88.
The speeds of sound in air and aluminum
are,
respectively, 340 m/sec and 5200 m/sec.
What
are the respective wavelengths in air and
alu-
minum of a 3600 Hz sound wave?
A.
0.28 m and 5.52 m
B.
0.09 m and 1.44 m
C.
0.28 m and 2.88 m
D.
1.34 m and 0.28 m
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