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A series circuit contains a 30 Ω resistor, a 20 Ω resistor, and a 10 Ω resistor. The power supply provides 100 V to the circuit. The current in the 10 Ω resistor, to two significant figures, is A.
1.7
The electric field between two parallel plates has a magnitude of 875 N/C. The positive plate is 0.002 m away from the negative plate. What is the electric potential difference between the plates?
1.8 × 100 V
A photon has a frequency of 2.9 × 10-16 Hz. Planck's constant is 6.63 × 10-34 J•s. The energy of the photon, to the nearest tenths place, is × 10-49 J.
1.9
A charge of 24 µC is at a location where the electric potential is 8.0 V. What is the electric potential energy of the charge?
1.9 × 10-4 J
Which equations can be used to calculate the electric potential energy stored in a capacitor? Check all that apply.
1/2 qv 1/2 cv2 q2/2c
Which equation is used to calculate the magnetic force on a charge moving in a magnetic field?
F = |q|vBsin
What is the equation for calculating the electrical force, Fe, between two charges?
Fe = k d2
How does gamma decay differ from both alpha decay and beta decay?
No new element forms.
What is the energy of a photon with a frequency of 2.2 × 1016 Hz? Planck's constant is 6.63 × 10-34 J•s.
1.5 × 10-17 J
The magnetic field 0.02 m from a wire is 0.1 T. What is the magnitude of the magnetic field 0.01 m from the same wire?
0.2
The nuclear equation is incomplete. What particle completes the equation?
138 54
The half-life of cobalt-60 is 5 years. How old is a sample of cobalt-60 if only one-eighth of the original sample is still cobalt-60?
15
A circuit has a current of 3.6 A and a resistance of 5.0 Ω. What is the voltage applied to the circuit?
18
Calcium-51 has a half-life of 4.5 days. Only 0.75 gram remains of a sample that was initially 12 grams. How old is the sample of calcium-51?
18
Current 1 of 8.4 A runs for 240 seconds and then stops. Current 2 is 10.5 A. How long does current 2 have to run to deliver the same amount of charge as current 1?
192
A power source of 6.0 V is attached to the ends of a capacitor. The charge is 12 C. What is the capacitance for this capacitor?
2.0 μF
A source charge generates an electric field of 1236 N/C at a distance of 4 m. What is the magnitude of the source charge?
2.2 µC
A proton is moved from a position where the electric potential is 125 V to a position where the electric potential is 275 V. The magnitude of the charge on a proton is 1.602 × 10-19 C. What is the change in electric potential energy of the proton?
2.4 × 10-17 J
How are electric potential difference and electric potential energy related?
Electric potential difference is the difference in electric potential energy divided by the charge.
The strength of the electric field 0.5 m from a 6 µC charge is N/C. (Use k = 8.99 × 109 N• and round answer to the nearest whole number.)
215,760
A power source that provides a current of 1.6 A to two 5 Ω resistors connected in series is moved to a parallel circuit that consists of three identical resistors. In the parallel circuit, the overall current is 2.0 A. The value of a resistor used in the parallel circuit is 5.38.012✔ 24 Ω.
24
A proton is moved so that its electric potential energy increases from 2.0 × 10-18 J to 6.0 × 10-18 J. The magnitude of the charge on a proton is 1.602 × 10-19 C. The electric potential difference through which the proton moved, to the nearest whole number, is V.
25
A 60-g sample of radioactive isotope is measured after two half-lives have passed. What pair of percentages describes the sample after two half-lives?
25% unchanged and 75% stable
A wire delivers 12.0 C of charge in 4.0 s. What is the current in the wire?
3
A source charge generates an electric field of 4286 N/C at a distance of 2.5 m. What is the magnitude of the source charge?
3.0 µC
According to Einstein, nothing in the universe can move faster than which approximate speed?
3.0 × 108 m/s
What is the electric field between two parallel plates if the electric potential difference between the plates is 24 V and the plates are 65 mm apart?
369
A circuit has a resistance of 2.5 Ω and is powered by a 12.0 V battery. The current in the circuit, to the nearest tenth, is A.
4.8
A charge of +0.08 C moves to the right due to a 4 N force exerted by an electric field. What is the magnitude and direction of the electric field?
50 N/C right
The electric field between two parallel plates has a magnitude of 1250 N/C. The positive plate is 0.05 m away from the negative plate. The electric potential difference between the plates, rounded to the tenths place, is V.
62.5
A point charge of 6.0 C is placed 5.0 mm from a rod that has an electric field of 2.4 N/C. The electric potential energy of the point charge (rounded to two significant figures) is J.
72
What is the formula for calculating the energy of a photon?
E = hf
A capacitor stores 6.2 × 10-8 C of charge and 2.4 × 10-6 J of energy. What is the capacitance of the capacitor?
8.0 × 10-10 F
Which are disadvantages of series circuits? Check all that apply.
A break in one wire causes all current to stop. If one bulb goes out, the others go out.
Lionel explores electromagnetic induction using the procedure shown. 1. Move the magnet quickly into the right end of a solenoid.2. Hold the magnet in the solenoid for 3 s.3. Move the solenoid slowly to the left away from the magnet. What should Lionel observe during his investigation?
A large current forms, drops to zero, then a smaller current forms in the opposite direction.
What is the relationship between radiopharmaceuticals, tracers, and radionuclides?
A radionuclide is part of a radiopharmaceutical, which functions as a tracer.
Which statement correctly describes the formation of an electric current?
A voltage causes electric charges to move from higher to lower potential.
Humberto builds two circuits using identical components. Circuit 1: A series circuit with three lightbulbsCircuit 2: A parallel circuit with three lightbulbs He then adds two more lightbulbs in a series with the bulbs in circuit 1 and two more lightbulbs on new branches in parallel with each bulb in circuit 2. What can he expect to see?
All bulbs in circuit 1 will shine more dimly than the original bulbs, while all bulbs in circuit 2 will have the same brightness as the original bulbs.
Which statement correctly describes mass-energy equivalence?
All energy in the universe is a result of mass being converted into energy.
Yanni is sitting in the stands watching a football game. The quarterback runs forward toward the end zone and throws a pass straight downfield to a player for a touchdown. The quarterback ran at a speed of 8 m/s and threw the ball with a speed of 15 m/s. Which statement is supported by this scenario?
For Yanni, the speed of the ball is 23 m/s, and for the quarterback, the speed of the ball is 15 m/s.
How does refraction support the particle theory of light?
Forces act on the particles to push or pull them from one medium to another.
How does the north pole of a magnet respond to the poles of other magnets?
It attracts the south pole and repels the north pole.
An iron nail does not pick up paper clips as a magnet would. What can be concluded about the structure of the iron nail?
It has domains that are not aligned.
Which describes the magnetic field that forms when a wire carries an electric current?
It is in a cylinder around the wire.
Rami uses a disposable camera that has a flash. When he wants to take a picture, he holds a button and hears a rising whining sound. When a small light glows, the flash is ready. He presses the shutter button, the flash lights up, and he takes his picture. Which statement best describes how a capacitor is useful in the camera?
It stores energy and delivers it in a short burst.
A magnetically soft material is placed in a strong magnetic field. What is the most likely outcome?
It will become a temporary magnet because the domains will easily realign.
Carlos arranges his notes about radioactive decay in a graphic organizer. He wants to add the labels shown. Label 1: PhotonLabel 2: PositronLabel 3: No change in mass number Which is the best region for each label?
Label 1: XLabel 2: ZLabel 3: Y
What did the accident at the nuclear power plant in Chernobyl in 1986 demonstrate about the use of nuclear power that had not been previously demonstrated?
Large areas can be contaminated with radiation.
What are characteristics of absorption spectra? Check all that apply.
Light is absorbed, which produces characteristic lines. Lines are dark on a visible light background. Lines are produced by electrons being excited.
Which imaging technique uses radiation that is emitted from the material being imaged?
MRI
Wilam made a chart to summarize the results of experiments with the photoelectric effect. Which best describes how to correct Wilam's error?
The first result should state that frequencies of light that were lower than the frequency threshold of the metal could not eject electrons.
For a constant voltage, how is the resistance related to the current?
Resistance is inversely proportional to current, so when the resistance doubles, the current is cut in half.
In a movie, the heroine saves the day by cutting a wire before the time runs out on a timer. How did she change the circuit?
She changed a closed circuit to an open circuit.
A doctor thinks a patient has an intussusception, in which a part of the intestine slides inside itself like the parts of a collapsible telescope. Which imaging technique is the doctor most likely to use? Explain.
Sonography is most likely because it has good resolution without radiation.
What is the result of changing the dielectric in a capacitor to a dielectric with a larger dielectric constant?
The capacitor can store more charge at a given potential difference.
Jason sees a news report about a traffic jam caused by a truckload of tires that spilled across the road. The next day in class, he uses the traffic jam as an analogy to explain electric circuits to his friend. Which is most likely the analogy that Jason used?
The cars represent moving charges, and the spilled tires represent an increased resistance that causes the current to decrease.
Sally is concerned about the X-ray images her dentist plans to take of her teeth. She has read that X-rays can cause tissue effects, such as skin reddening and hair loss. Which statement would best inform Sally of the level of risk?
The dentist uses X-ray radiography, which takes too short a time to cause those problems.
A negative test charge experiences a force to the right as a result of an electric field. Which is the best conclusion to draw based on this description?
The electric field points to the left because the force on a negative charge is opposite to the direction of the field.
The table lists the values of the electrical force and the gravitational force between two protons. How do the electrical force and the gravitational force compare?
The electrical force is 1.2 × 1036 times greater than the gravitational force.
Which best explains what happens when an electron moves from an excited state to the ground state?
The electron releases energy as it moves to a lower energy level.
Which describes a relationship when calculating the energy of a photon?
The energy of the photon is directly proportional to frequency.
Which describes time dilation?
The faster an object moves, the more stretched time becomes.
Joan makes the device shown in her science class. What would happen to the magnetic field if she connects the battery in the opposite direction?
The field would reverse its poles.
Which statements correctly compare the gravitational force with the electrical force? Check all that apply.
The gravitational force can be attractive. The electrical force can be repulsive. The electrical force can be attractive. Any two objects experience a gravitational force between them.
The north pole of a strong magnet is dragged down an iron nail from the top to the point 50 times. What will most likely happen when the nail is brought near a pile of small paper clips?
The nail will pick up some paper clips because its domains have been aligned.
Which describes why radioisotopes can be used as tracers in studying the biological and chemical processes of plants?
The radioisotope is chemically identical to the nonradioisotope the plant normally uses.
Basim's robotics team builds a robot that travels at 9 m/s and can fire a tennis ball at a target. Which would result in a judge who is sitting beside the testing ground observing the tennis ball having a speed of 7 m/s?
The robot fires the ball backward with a speed of 2 m/s.
Frank stands still while throwing a dart toward a target with a speed of 25 m/s. What is the speed of the dart observed by Frank compared to the speed observed by a stationary observer?
The speed is 25 m/s for both people.
Which statement is supported by Einstein's postulates of special relativity?
The speed of light through empty space is constant regardless of the state of motion of the observer.
Alyssa is carrying a water balloon while running down a field at a speed of 14 m/s. She tosses the water balloon forward toward a bucket with a speed of 23 m/s. Alyssa's friend Naya is standing still next to the field. Which statement is supported by this scenario?
The speed of the balloon is 23 m/s for Alyssa and 37 m/s for Naya.
The cause of a fire in a computer is described as an incorrectly wired circuit. Which statement best explains the likely cause of the fire?
The wiring contained a short circuit, so the reduced resistance caused an increase in current.
Both the electrical force and the gravitational force between two objects share which relationship?
They are inversely proportional to the square of the distance.
A bar magnet is placed on a table so that the north pole faces right. Which statement describes the magnetic field lines 2 cm above the table?
They are pointing right to left.
Which theory was contradicted by experiments with the photoelectric effect?
Visible light, regardless of color, will cause the ejection of electrons when striking metal.
Which describes the results of the double slit experiment? Check all that apply.
Waves produced a diffraction pattern. Results supported the wave theory of light.
This image shows a stream of positively charged particles being directed at gold foil. The positively charged particles are called "alpha particles" and each one is like a nucleus without any electrons. What is the best explanation for why a particle is striking point X?
When the dense, positive alpha particle passes close to a positive nucleus of gold, the alpha particle repels and hits the screen at point X.
The magnetic field 0.01 m from a wire carrying a current of 20 A is 0.004 T. The current in the wire and the distance from the wire are changed, as recorded in the table. Which values belong in cells X and Y of the table?
X: 0.002Y: 0.006 option d
Gazala makes a graphic organizer to compare nuclear fission and nuclear fusion. Which labels belong in the regions marked X and Y?
X: Converts mass into energyY: Is controlled by neutron absorption
Wendy makes a graphic organizer to help herself apply Ohm's law to electric circuits. Which formulas belong in the regions marked X and Y?
X: Req = R1 + R2 + R3Y: I = answer b
Sadira makes a graphic organizer to show how geologists and archaeologists use radioisotopes. Which labels belong in the regions marked X and Y?
X: Uses uranium-238Y: Determines ages of objects
Which transition by an electron will release the greatest amount of energy?
a
When the north pole of a bar magnet is moved into a solenoid, the needle on a galvanometer attached to the solenoid moves to the left, indicating that a current is produced. The magnet is then pulled out at a faster speed. What will be the result?
a larger current in the opposite direction
What are the starting materials for nuclear fission?
a neutron and a large nucleus
What is the smallest packet of electromagnetic energy that can be absorbed or emitted?
a quantum
A circuit that has only a single path for current to flow through is best classified into which category?
a series circuit
Which will produce a magnetic field?
a wire carrying a current
What type of spectrum is shown below?
absorption
As part of the photoelectric effect, which of these is responsible for the pixels in an image on a digital camera?
accumulated electrons that are ejected by the image sensor
Which therapeutic application involves the placement of a pellet of radioactive material near a tumor?
brachytherapy
Craig is modeling the discovery of electromagnetism. Which procedure should he use?
bringing a compass near a wire that has an electric current
Which therapy is associated with light, but not sound?
cauterizing an incision or wound
This diagram shows the magnetic field lines near the ends of two magnets. There is an error in the diagram. Which change will correct the error in the diagram?
changing the S to N
Which factors affect the electrical force between two objects?
charge and distance between them
A wire has a current that flows to the right. Which describes the magnetic field produced by the current?
circles around the wire that go in at the bottom
What is the continuous flow of electric charge?
current
The insulating material placed between the conducting plates of a capacitor is a(n) .
dielectric
Time is a phenomenon in which objects in motion and objects at rest experience time differently.
dilation
A pair of opposite electric charges of equal magnitude is called a(n)
dipole
A cluster of atoms whose magnetic fields are aligned in the same direction is a magnetic .
domain
Which equation represents mass-energy equivalence?
e=mc2
While solving a problem, Sue calculates an answer that has the units . Which quantity did Sue find for her answer?
electric potential difference
While solving a problem, Tran calculates an answer that has coulomb-volts as the units. Which quantity did Tran calculate?
electric potential energy
What is released when an excited electron returns to a lower energy state?
electromagnetic radiation
The generation of a magnetic field by an electric current is .
electromagnetism
Changes in the appearance of emission and absorption spectrums are caused by the activities of
electrons
The area around a charged object that can exert a force on other charged objects is an electric .
field
When using the right-hand rule to determine the direction of the magnetic field around a current-carrying wire, which part of the right hand points in the direction of the magnetic field?
fingers
The table below shows the wavelengths of visible light that correspond to different colors. A student analyzes the emission spectrum of an unknown element and observes strong lines at the following wavelengths: 656 nm, 486 nm, 434 nm. Which absorption spectrum is the student most likely viewing?
first one
Which actions most likely cause the domains within a material to lose their alignment and become more randomized? Check all that apply.
heating the material placing the material in a magnetic field of opposite polarity hitting the material
What conditions are required for nuclear fusion?
high temperature and high pressure
Which changes would cause an increase in the resistance of a wire? Check all that apply.
increasing its temperature using a longer wire using a thinner wire
Steel objects can become temporary magnets because they are mainly composed of which element?
iron
What is the direction of the electric field at a point directly to the left of a positive charge, Q?
left
The diagram shows a negative charge moving in a magnetic field. In which direction is the magnetic force acting on the charge?
lrft
What is the unit for resistance?
ohm
A positive charge, q1, of 5 µC is 3 × 10-2 m west of a positive charge, q2, of 2 µC. What is the magnitude and direction of the electrical force, Fe, applied by q1 on q2?
magnitude: 100 Ndirection: east
The emission spectrum of the element lithium is shown below. What is the best estimate of the color that will be seen when a sample of lithium gas absorbs a lot of energy?
mix of red and orange
Suppose a rocket is traveling through space and moving at a speed close to the speed of light. Three minutes pass on the rocket as recorded by an observer on Earth. How many minutes pass on Earth?
more than three minutes because of time dilation
Tonya is modeling the discovery of electromagnetic induction. Which procedure should she use?
moving a magnet into a coil of wire in a closed circuit
Which are associated with nuclear fission but are not associated with nuclear fusion? Check all that apply.
neutrons striking nuclei a single large nucleus breaking apart two small nuclei forming
Gertrude writes a short story in which the main character must enter a nuclear-powered spaceship's engine room that has lost its shielding in order to prevent the engine from flooding the rest of the ship with radiation. The main character is not wearing protective gear. What effects are best for Gertrude to consider when planning what may happen to the character?
non-stochastic effects such as severe burns and radiation sickness resulting from the short-term, high-level exposure
Carla sees an equation that models a nuclear change. Which nuclear process does the equation illustrate?
nuclear fusion, because the equation shows two hydrogen nuclei combining to form a helium nucleus
A noncontinuous loop that prevents the flow of current is a(n) circuit.
open
What is the measure of how much a material resists the formation of an electric field?
permittivity
Which is the best procedure to make a permanent magnet?
placing a magnetically hard material in a strong magnetic field
Any radiation treatment has the potential to damage DNA in healthy cells. Which lists therapeutic uses of radiation based on the likelihood of affecting healthy cells in order from least likely to most likely?
radiopharmaceuticals, brachytherapy, deep external beam radiation therapy
A positive charge moving up enters a magnetic field pointing out of the screen. What is the direction of the magnetic force on the charge?
right
A coil of wire that carries an electric current is a(n) .
solenoid
What is the half-life of a radioisotope?
the time needed for half of a sample of radioisotope to decay
What must be known to determine the direction of the magnetic force on a charge? Check all that apply.
the type of the charge the direction of the magnetic field the velocity of the charge
According to the special theory of relativity, what is the fourth dimension?
time
Why are the plates in a capacitor parallel to each other?
to form a uniform electric field between the plates
The use of radioisotope imaging is best suited for which procedure?
to monitor the function of an enzyme in the cells of the pancreas
The diagram shows a positive charge moving in a magnetic field. In which direction is the magnetic force acting on the charge?
up
Which are methods of reducing exposure to ionizing radiation? Check all that apply.
using a lead apron during medical X-rays using a short burst of X-rays to take an image taking an image of the smallest possible area
Julia produces a 2 mA current by moving the south pole of a bar magnet into a solenoid. The solenoid contains 150 loops of wire. Which change should Julia make to generate a larger current?
using more loops of wire in the coil
Keisha analyzes this circuit diagram. Which circuit component should Keisha use to start or stop the current in the circuit?
w
Three charges are located at the vertices of a triangle, as shown. Which vector best represents the net force acting on the -3 C charge in the diagram?
w
The diagram shows the electric field in the vicinity of a charge. At which point is the electric field strongest?
y