1. No category

my account
Enter keyword(s)
Home
Registration
Test Prep
Scores
Practice Questions:
Passage 1
Passage 2
College Planning
English
Passage 3
Math
Passage 4
Financial Aid
Career Planning
Reading
Science
Passage 5
Passage 6
Student Blog
FAQs
Writing
Passage 7
SAMPLE SCIENCE TEST QUESTIONS
DIRECTIONS
Click on the letter choices to determine if you have the correct answer and for question explanations.
An actual ACT Science Test contains 40 questions to be answered in 35 minutes.
DIRECTIONS: The passage in this test is followed by several questions. After reading the passage, choose the
best answer to each question and fill in the corresponding oval on your answer document. You may refer to the
passage as often as necessary.
You are NOT permitted to use a calculator on this test.
Passage VII
A photocell is a device for generating an electrical
current from light (see Figure 1).
1. Based on Table 1, which of the following
statements best explains the results of Trials 1–3 ?
A. The light was too intense to eject
electrons from the metal in the photocell.
B. The light was too intense to eject photons
from the metal in the photocell.
C. The energy per electron was too high to
eject photons from the metal in the
photocell.
D. The energy per photon was too low to
eject electrons from the metal in the
photocell.
2. Consider the following results, obtained using
5.0 eV photons and the same photocell that is
discussed in the passage.
Figure 1
Each photocell contains a metal. A photon of light that
strikes the metal can eject an electron from the metal if the
photon's energy exceeds the metal's work function. The
maximum kinetic energy the ejected electron can have is the
photon's energy minus the metal's work function. The amount
of electrical current varies with light's relative intensity (a
Relative
intensity
of light
Electrical
current (mA)
Maximum kinetic
energy of ejected
electron (eV)
low
medium
28
42
3.1
3.1
of electrical current varies with light's relative intensity (a
measure of the number of photons with a given energy
striking the metal each second).
Table 1 shows the results of 9 trials in which a photocell
was exposed to light.
1
2
3
4
5
6
7
8
9
2.0
2.0
2.0
4.0
4.0
4.0
6.0
6.0
6.0
low
medium
high
low
medium
high
low
medium
high
58
3.1
The maximum kinetic energy of the ejected
electron, 3.1 eV, was not the expected value. The
expected value was:
F. 0.0 eV.
G. between 0.1 eV and 0.8 eV.
H. between 0.9 eV and 2.9 eV.
Table 1
Energy
Relative
per photon intensity of
Trial
(eV)*
light
high
Electrical
current
(mA)†
Maximum
kinetic
energy of
electron if
ejected from
metal (eV)
0
0
0
29
43
60
27
40
55
0.0
0.0
0.0
0.9
0.9
0.9
2.9
2.9
2.9
*eV = electron volts
†mA = milliamps
J. greater than 3.0 eV.
3. When 8.0 eV photons were shone on the photocell,
electrons ejected from the metal in the photocell
had a maximum kinetic energy of 4.9 eV. Based
on this information and Table 1, the relative
intensity of the light shone on the photocell:
A. was high.
B. was medium.
C. was low.
D. cannot be determined.
4. Based on the passage and Table 1, the work
function of the metal used in the photocell was:
F. 2.0 eV.
G. 3.1 eV.
H. 4.9 eV.
J. 6.0 eV.
5. In the photocell discussed in the passage, suppose
the work function of the metal had been 5.1 eV. If
the energy per photon had been the same as in
Trials 7–9, the maximum kinetic energy of
electrons that were ejected from the metal would
have been:
A. 0.9 eV.
B. 2.0 eV.
C. 4.0 eV.
D. 5.1 eV.
© 2011 by ACT, Inc. Terms of Use | Privacy Policy | Ethics and Compliance
ACT Corporate Home | Contact Us | Site Index