8th Grade Integrated Science
Unit 3 – Energy: Assessment
Version: A
UNIT 3 ASSESSMENT - ALIGNMENT GUIDE
Objective
Number
2d
2e
Objective
Item
Numbers
Total
Questions
1 – 13
13
14 – 26
13
Relate how electrical energy transfers through electric circuits,
generators, and power grids, including the importance of
contributions from Mississippi companies. (DOK 2)
Contrast various components of the electromagnetic spectrum
(e.g., infrared, visible light, ultraviolet) and predict their impacts
on living things. (DOK 2)
TOTAL:
26
Directions: Answer these questions to the best of your ability. Be sure to read the
question completely to understand what is being asked of you! Write only on your
answer document.
1. Power grids use alternating current (AC) in transmission and distribution systems.
Which statement explains why AC is used instead of direct current (DC)?
A. Transmission wires cannot carry enough direct current to supply the needs of the power grid.
B. The voltage can be changed in an alternating current system to transfer energy more efficiently.
C. Electrical energy must be transmitted as alternating current because that is how it is produced at
power plants.
D. Direct current would not be useful to electric company customers because appliances operate on
alternating current.
2. Which of these describes a step-up transformer?
A. As it decreases voltage, it is located at a power substation and feeds into the distribution network.
B. Step-up transformers increase voltage and are located at power substations for distribution.
C. Found at a transmission substation, it increases the voltage of electricity for long journeys.
D. Since it decreases voltage, it is located at a transmission substation where it can then be distributed.
3. Which list shows the path of electricity from a local power substation to a lamp in a home?
A. Transformer → distribution power lines → outlet →electric circuit of lamp
B. Transformer → distribution power lines → transformer → outlet →electric circuit of lamp
C. Distribution power lines → outlet → transformer → electric circuit of lamp
D. Distribution power lines → transformer → outlet → transformer → electric circuit of lamp
A student builds a simple electric circuit to light a light bulb according to the diagram shown at the right.
Use this information and the diagram to answer questions 4 – 8.
4. Which of these components in the circuit is a battery?
5. Which of these components in the circuit is a light bulb?
6. Which of these describes how electrons flow through the circuit?
A. From the positive terminal of the power supply to the negative
terminal.
B. Electrons flow in both directions through the circuit to light each
resistor.
C. The electrons move from the negative terminal of the power supply
to the positive terminal.
D. Electrons will not flow through the circuit because it does not form a closed loop.
7. Which of these correctly classifies the type of circuit shown above?
A. The circuit’s resistors are in series.
B. The resistors are in a parallel configuration.
C. It is both a series and parallel circuit as the resistors are at a right angle to one another.
D. It is not possible to determine the circuit’s configuration without experimenting with the circuit.
8. If the total resistance in the circuit is 10Ω and the voltage of the power supply is 24 volts, how much current
will be moving through the wire? You must include the correct units to receive full credit.
9. An electrical engineer is designing a circuit that will run a Geiger counter. He tests his current version of
the circuit and measures that the number of electrons passing through the circuit is 7.5 and the resistance of
the wires in the circuit is 20Ω.
According to Ohm’s Law, which of the following is true?
A. The number of electrons passing through the wire will decrease to 27.5 amps.
B. The number of electrons passing through the wire will increase to 150 amps.
C. The electrons are being pushed through the wire with a force of 27.5 volts.
D. The electrons are being pushed through the wire with a force of 150 volts.
10. The electrical engineer’s design for the circuit to run his Geiger counter is
shown at the right.
Which of these describes the circuit?
A. All of the resistors in the circuit are setup in parallel.
B. All of the resistors in the circuit are setup in series.
C. Resistors 2 and 3 are in parallel but resistors 1 and 2 as well as 1 and
3 are in series.
D. Resistors 2 and 3 are in series but resistors 1 and 2 as well as 1 and 3 are in parallel.
11. Which of these describes the relationship between a generator and a turbine?
A. Mechanical energy from a moving fluid is converted to chemical energy by a generator-turbine.
B. Chemical energy stored in steam or air is converted to mechanical energy by a turbine then to
electrical energy by a generator.
C. A turbine captures mechanical energy and transfers this energy to the generator.
D. A generator is used to turn a turbine, converting electrical energy to mechanical energy.
12. A nuclear power plant uses nuclear fuel such as uranium to produce electrical energy. These steps of this
process are shown below.
I.
A turbine captures this mechanical energy and spins
II.
Water boils producing steam
III.
Nuclear fission occurs and uranium atoms split, releasing neutrons and energy
IV.
A coil of wire is turned inside a magnet causing electrons to move
Which of these puts the steps of this process in the correct order.
A. I, II, III, IV
B. III, IV, II, I
C. IV, I, II, III
D. III, II, I, IV
13. Which of these is NOT a source of thermal energy that can be converted to mechanical energy and then
used to produce electricity?
A. Concentrated sunlight
B. Water through a dam
C. Burning coal
D. Nuclear fission
14. Infrared light is often used in reptile habitats.
Which of these explains how a reptile benefits from infrared light?
A. Infrared light destroys bacteria and other microorganisms.
B. Infrared light increases the body temperature of the animals.
C. Infrared light makes it possible for reptiles to see their surroundings.
D. Infrared light makes it possible for humans to see the animals in their natural habitat.
15. Which type of electromagnetic
wave has a wavelength longer
than that of yellow light?
A. Infrared Radiation
B. UV Rays
C. X-rays
D. Gamma Rays
16. Doctors attempt to minimize the number of x-rays that a patient receives. Which of the following explains
this decision?
A. X-rays are very expensive to produce because of their high energy.
B. Since x-rays are very high energy, they can damage DNA and could possibly hurt a patient.
C. X-rays do not give a clear picture of the inside of a human body thus doctors prefer images made
using gamma rays.
D. As doctors do not yet know the effects of x-rays, they are cautious about exposing patients to them.
17. Quandarius is learning about different types of electromagnetic radiation. He makes the following list about
one frequency of radiation:
• Very short wavelengths
• Able to pass through human body
• Very damaging to cell DNA.
Which type of radiation does Quandarius’ list describe?
A.
B.
C.
D.
Infrared
Visible
Ultraviolet
X-Ray
18. A sewer system operator would like to use electromagnetic radiation to destroy bacteria and other organisms
in filtered wastewater before it is released into the environment.
Which type of electromagnetic radiation is capable of treating the wastewater?
A. Ultraviolet
B. Infrared
C. Visible
D. Radio
19. A t-shirt manufacturer is about to begin production of new a new style of t-shirt. The designer wants the
shirts to be green.
Which of these describes the molecules of dye that that should be used to color the shirts?
A. The molecules should absorb all wavelengths of visible light.
B. The molecules should reflect all wavelengths of visible light.
C. Only green wavelengths of visible light should be reflected, all others should be absorbed by the
molecules.
D. Only green wavelengths of visible light should be absorbed, all others should be reflected by the
molecules.
m
20. A student is studying an earthquake wave which she reads has a velocity of 500 s and a frequency of 25 Hz.
What is the wavelength of this earthquake wave? You must include appropriate units to receive full credit.
21. Which of these describes the relationship between frequency and energy?
A. As the frequency of a wave decreases, the amount of energy carried by the wave increases.
B. As the frequency of a wave increases, the amount of energy carried by the wave increases.
C. There is no relationship between the frequency of a wave and its wavelength.
D. The relationship given in answer choice A describes sound waves while choice B describes
electromagnetic waves.
22. Assuming that are all traveling at the same velocity, which of these electromagnetic waves has the least
amount of energy?
A. A gamma ray from a distant start with a wavelength of 10-6 nanometers.
B. A radio wave with a wavelength of approximately 75 kilometers.
C. A microwave with a wavelength of 12.3 millimeters.
D. An x-ray produced by a CT scanner with a wavelength of 5 nanometers.
23. A biomedical engineer is producing a machine that releases UV rays, an electromagnetic wave, that will be
used to sterilize medical equipment. The wave has a wavelength of 1 x 10-7 m. Which of these is the
frequency of this UV ray?
A. 3 x 1015 Hz
B. 3 x 10-1 Hz
C. 3 x 10-56
D. 3 x
m
s
m
1015 s
24. A certain object is reflecting electromagnetic waves with a wavelength between 380 and 750 nanometers.
What color will this object be?
Color
25. A company in Laurel, Mississippi produces school buses. The
paint that is used to paint the school buses must absorb certain
wavelengths of visible light and must reflect other wavelengths
such that the bus is yellow in color. Which of these correctly
describes the way visible waves should interact with this paint so
that the bus is yellow.
A. Only 570 – 590 nanometer waves should be reflected.
B. Waves with a wavelength from 380 – 570 nanometers as
well as waves with a wavelength between 590 and 750
nanometers should be reflected.
C. All wavelengths of light should be absorbed.
D. All wavelengths of light should be absorbed.
Violet
Indigo
Blue
Green
Yellow
Orange
Red
Frequency
668–789 THz
631–668 THz
606–630 THz
526–606 THz
508–526 THz
484–508 THz
400–484 THz
Wavelength
380–450 nm
450–475 nm
476–495 nm
495–570 nm
570–590 nm
590–620 nm
620–750 nm
26. A scientist is comparing two lasers she finds in a catalog. The first laser is a helium-cadmium laser with a
wavelength of 442 nanometers. The second laser is a krypton laser with a wavelength of 647 nanometers.
Which of these describes the laser that she would choose if she wants the strongest laser possible?
A. The krypton laser
B. The helium-cadmium laser
C. Either as they release light with the same amount of energy.
D. It is impossible to determine which she should pick without purchasing the two lasers and testing
them in a laboratory.