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NNHS Introductory Physics: MCAS Review
Packet #4
Introductory Physics, High School
Learning Standards for a Full First-Year Course
I. CONTENT STANDARDS
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as electricity
and magnetism.
5.1 Recognize that an electric charge tends to be static on insulators and can move on and in
conductors. Explain that energy can produce a separation of charges.
5.2 Develop qualitative and quantitative understandings of current, voltage, resistance, and the
connections among them (Ohm’s law).
5.3 Analyze simple arrangements of electrical components in both series and parallel circuits.
Recognize symbols and understand the functions of common circuit elements (battery,
connecting wire, switch, fuse, resistance) in a schematic diagram.
5.4 Describe conceptually the attractive or repulsive forces between objects relative to their charges
and the distance between them (Coulomb’s law).
5.5 Explain how electric current is a flow of charge caused by a potential difference (voltage), and
how power is equal to current multiplied by voltage.
5.6 Recognize that moving electric charges produce magnetic forces and moving magnets produce
electric forces. Recognize that the interplay of electric and magnetic forces is the basis for electric
motors, generators, and other technologies.
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
1.) The diagram below shows two aluminum
2.) Why does a plastic rod have a negative
spheres.
charge after being rubbed with a piece of fur?
A. The fur gives up protons to the rod.
B. The rod gives up electrons to the air.
C. The fur gains protons from the rod.
D. The rod gains electrons from the fur.
Aluminum sphere A contains a small negative
charge and is touched by aluminum sphere B,
which has a larger negative charge. Which of
the following occurs next?
A. Protons flow from sphere B to sphere A.
B. Protons flow from sphere A to sphere B.
C. Electrons flow from sphere B to sphere A.
D. Electrons flow from sphere A to sphere B.
My Answer and Explanation:
My Answer and Explanation:
C. Electrons are the only particles that are
able to flow in solids because protons are
larger and bound in the nucleus. The
electrons will flow to even out the charge
over both spheres.
D. Electrons, not protons, are transferred. If
something has a negative charge, it is
because it gained electrons. The rod gained
the electrons that the fur lost.
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as electricity and
magnetism.
3.) A negatively charged rubber rod was
brought near some small pieces of paper. The
rod’s charges repelled the negative charges in
the pieces.
Which of the following caused the repulsion of
the negative charges?
A. conduction
B. gravitation
C. induction
D. insulation
4.) The figure below shows a neutral glass rod
and a positively charged metal sphere.
Which of the following best describes the
movement of charges as this glass rod touches
the sphere?
A. Negative charges move from the sphere to
the glass rod.
B. Negative charges move from the glass rod
to the sphere.
C. Positive charges move from the sphere to
the glass rod.
D. Positive charges move from the glass rod to
the sphere.
My Answer and Explanation:
My Answer and Explanation:
C. Induction is what causes charges to
move in objects that are not touching. It is
due to the electrical force between the
objects that can act at a distance (the way
gravity and magnetic forces can).
B. Only electrons are able to conduct
through solids. The positive dome attracts
some of the rod’s electrons.
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as electricity and
magnetism.
5.) Which of the following describes an object
that must have a net negative charge?
A. It contains more molecules than atoms.
B. It contains more electrons than protons.
C. It is carrying an electric current.
D. It is made of metal.
6.) An electric circuit is shown below. The
accompanying table shows the current
measured at different levels of resistance.
Based on the data shown in the table, what is
the voltage drop across the variable resistor?
A. 1.5 V
B. 6 V
C. 9 V
D. 12 V
My Answer and Explanation:
My Answer and Explanation:
B. Net charge is when there is a surplus of
one type of charge. If it is a net negative
charge, then there must be extra electrons.
The voltage provided by a battery is entirely
consumed by the devices in the circuit, so
use Ohm’s law to find the voltage, using the
current and resistance. Since the voltage of
the battery does not depend on what is in
the circuit, any of the R and I values will
give the same answer.
R = .1 
I = 15A
V = IR = (.1)(15)
V = 1.5V
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
7.) Mr. Jenkins constructed a circuit consisting 8.) What is the voltage in a circuit with a
of a variable source, wires, and a resistor. In
current of 3 Amps and a total resistance of 12
order to triple the amount of current, how
?
should he change the voltage of the source?
A. 0.25 V
A. make the voltage three times larger
B. 4 V
B. make the voltage one-third as great
C. 15 V
C. make the voltage nine times larger
D. 36 V
D. make the voltage one-ninth as great
My Answer and Explanation:
My Answer and Explanation:
A. Ohm’s law explains that current is
directly proportional to the voltage and
inversely proportional to resistance. To
triple the current, you could either triple the
voltage or make the resistance 1/3 as much.
Since the latter is not a choice, tripling the
voltage is the only correct answer.
D. Ohm’s Law:
V = IR, so V = 3A x 12  = 36V
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
9.) The circuit diagram below shows three
10.) Students in a physics lab are studying the
resistors, an ammeter, and a battery.
circuit shown in the diagram below.
How much current flows through the ammeter?
A. 1.0 A
Which of the following options will double
B. 6.0 A
the current through the ammeter?
C. 13.0 A
A. replacing the battery with a 5 V battery
D. 24.0
B. adding a 30  resistor in parallel with R
C. replacing the resistor with a 30  resistor
D. adding a second 60  resistor in series with
R
My Answer and Explanation:
My Answer and Explanation:
B. Voltage is equal across all branches of a
parallel circuit, so use Ohm’s law where V =
12 V and R = 2 .
I = 12/2 = 6 A
C. Ohm’s law again. Current is inversely
proportional to resistance. By cutting the
resistance in half, you can double the
current.
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
11.) A 72 W navigation unit on a commercial
12.) When a light bulb is turned on, energy
aircraft has a 24 V power supply and uses 3 A
changes from one form to another. Which of
of electric current. What is the electrical
the following best describes this change?
resistance of the navigation unit?
A. sound energy to light energy
B. nuclear energy to light energy
A. 4 
C. electrical energy to light energy
B. 8 
D. magnetic energy to light energy
C. 13 
D. 22 
My Answer and Explanation:
My Answer and Explanation:
Use Ohm’s law. R = V/I = 24/3 = 8 .
Since you’re looking for resistance, and you
already know the voltage and current, the
power is just extra information, which you
don’t need.
C. Electricity (moving electrons) experience
friction when going through the narrow
filament, and thus gives off heat and light.
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
13.) Marta has a radio in her room. It requires
14.) An ammeter measures the current in
electricity in order to play. Which of the
the circuit shown below.
following is necessary in order for electricity to
move from the source to the radio?
A. a circuit
B. a magnet
C. a light bulb
D. an insulator decreasing in volume.
My Answer and Explanation:
A. The path for the electrons must be a
complete loop, otherwise no electricity will
flow.
When the piece of wire labeled X is
replaced by a second identical R, which of
the following happens to the current?
A. It increases.
B. It decreases.
C. It goes to zero.
D. It remains unchanged.
My Answer and Explanation:
B. Adding another resistor in series with
the first will increase the resistance.
This will decrease the current
according to Ohm’s Law:
V=
Correct Answer and Explanation:
I
R
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
15.) A student combs her hair with a hard
rubber comb and then hangs the comb on a
loop of light thread that is suspended from a
hook as shown below.
She immediately combs her hair with a second
identical comb and hangs it on the second
suspended loop of light thread. If the combing
has caused a charge to accumulate on the
combs, which of the following shows what will
occur?
My Answer and Explanation:
B. Since both combs were charged using the
same technique (rubbing on hair), their
resulting charges will be the same. Two
objects with the same charge will repel.
Since there is a force from each comb on the
other, both combs will be pushed, so B is the
best answer.
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
16.) The figures below show a light bulb connected to a battery in two different ways.
When the switch in Figure 1 is closed the bulb will light. A plastic ring is inserted in the circuit as
shown in Figure 2. What will happen when the switch is closed in Figure 2?
A. The bulb will light just as it did in Figure 1.
B. The bulb will be brighter than it was in Figure 1.
C. The bulb will light, but will be less bright than it was in Figure 1.
D. The bulb will not light at all.
My Answer and Explanation:
D. Electrons need a continuous loop of conductive material in order to flow. The plastic ring
in the circuit is not a conductor, so the electrons in the wires will not be able to flow because
the circuit will not be complete.
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
My Answer and Explanation:
D. Only the penny is a conductor (it is metal), so
only the penny will allow the flow of electrons
through it.
17.)
A student is testing materials to see if
they conduct electricity. The student
places each item shown at position X,
making sure the object is in contact
with the loose end of each wire. Which
item will electricity flow through,
causing the bulb to light?
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
18.) In the diagram below, the circuit has
19.) A teenager removes the plastic
one battery and two identical light bulbs.
wrapping from a CD. The pieces of wrap
cling to her hand.
Which of the following forces causes the
wrap to cling to her hand?
A. electrostatic
B. gravitational
C. magnetic
D. net
If one light bulb is removed, which of the
following could replace it so that the
remaining light bulb is dimmer?
A.
B.
C.
D.
My Answer and Explanation:
C. Replacing the light bulb with a
resistor could make the current
lower than it had been, which
would make the bulb dimmer.
Choices A and D are just wires
with less resistance than the
bulb, so the remaining bulb
would be brighter.
Correct Answer and Explanation:
My Answer and Explanation:
A. The cling (also called “static
cling”) happens because the
plastic wrap is charged. When
it separated from the CD case,
it also separated some
electrons, making the plastic
wrap have one charge, while
the CD case has the opposite
charge.
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
5. Electromagnetism
Central Concept: Stationary and moving charged particles result in the phenomena known as
electricity and magnetism.
20.) The distance between two charges is
21.) A magnetic compass is placed near
represented by d. In which of the following an insulated copper wire. When the wire is
diagrams is the attractive force between the connected to a battery, the compass
needle changes position.
two charges the greatest?
Which of the following is the best
explanation for the movement of the
A.
needle?
A. The copper wire magnetizes the needle
to create a force.
B.
B. The needle magnetizes the copper wire
to create a force.
C. The current in the wire produces a
C.
magnetic field and exerts a force on the
needle.
D. The insulation on the wire becomes
D.
energized and exerts a force on the
needle.
My Answer and Explanation:
My Answer and Explanation:
B. Because both charges are
C. Moving charges are surrounded
doubled (compared to A), the
by magnetic fields. An electric
force is four times greater than
current is a flow of charges.
A.
C’s force is ¼ as much as A
(due to inverse square).
D’s force is equal to A.
Correct Answer and Explanation:
Correct Answer and Explanation:
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
Practice: Open-response question #1
BE SURE TO ANSWER AND LABEL ALL PARTS OF THE QUESTION.
Show all your work (diagrams, tables, or computations)
If you do the work in your head, explain in writing how you did the work.
Look at the objects shown below.
Some of these objects are conductors of electricity and some are insulators.
a. List all the objects that are conductors.
b. List all the objects that are insulators.
c. Describe the difference between a conductor of electricity and an insulator of electricity.
A. Conductors: paper clip, copper tubing, clothes hanger (assuming it’s metal)
B. Insulators: Rubber band, glass tube
C. The atoms in conductors have loosely bound electrons, so they allow electrons to move
easily throughout them, and of course, conduct electricity. The electrons in the atoms of
insulators are tightly bound to those atoms, so electricity cannot flow through them.
KEY
NNHS Introductory Physics: MCAS Review
Packet #4
Practice: Open-response question #2
BE SURE TO ANSWER AND LABEL ALL PARTS OF THE QUESTION.
Show all your work (diagrams, tables, or computations)
If you do the work in your head, explain in writing how you did the work.
A circuit with three identical light bulbs is shown in the diagram below.
QuickTime™ and a
decompressor
are needed to see this picture.
a. Identify the symbol labeled J in the circuit.
b. Describe what each light bulb does in each of the following situations:
• when switches 1 and 2 are open
• when switches 1 and 2 are closed
• when switch 1 is open and switch 2 is closed
• when switch 1 is closed and switch 2 is open
A. The symbol labeled J in the circuit represents a battery.
B. • When switches 1 and 2 are open, only Z is lit.
• When switches 1 and 2 are closed, all three bulbs are lit. (Z will be
as bright as when the switches were open.)
• When switch 1 is open and 2 is closed, only Z is lit.
* When switch 1 is closed and 2 is open, bulbs Z and Y will be lit.
(They will be as bright as when both switches were closed.)