PHY 104 Final
An object placed 20 cm in front of a diverging lens forms an image 4 cm in front of the lens. What is the focal length of the lens?
5.0 cm. -5.0 cm. 3.3 cm. -3.3 cm. B
The resolving power of a microscope is the focal length of the objective lens.
False
Which of the following is the correct loop equation starting from the tail of loop 1?
V1 - I1R1 + I2R2 - V2 = 0 I1 + I2 = I3 -V1 - I1R1 + I2R2 + V2 = 0 -V1 - I1R1 - I2R2 + V2 = 0 C
A slit 0.010 mm wide is illuminated with blue light (lambda=500 nm). How wide is the central maximum formed on a screen 0.5 m from the slit?
2.5x10^{-2} m 5.0x10^{-2} m 5.0x10^{-2} 1.25x10^{-2} m B
A proton travels at a speed of 3.0x10^(6) m/s through a uniform magnetic field whose magnitude is 8.0x10^(-3) T. What is the magnitude of the magnetic force on the proton if its velocity vector and the magnetic field vector are perpendicular?
3.8x10^(-18) N 0.0 N 3.8x10^(-15) 3.8x10^(-15) N D
In a flashing neon light circuit, a time constant of 1.2 s is desired. If you have a 3.0 micro-farad capacitor, what resistance should you use in the circuit?
4.0x10^(5) ohms 2.5x10^(-6) ohms 4.0x10^(5) 3.6x10^(-6) ohms A
You can increase the strength of a solenoid's magnetic field by inserting an iron core inside the coils of the solenoid.
True
Two sources of light send waves through a single slit. The images are resolvable
if the central bright spots of the individual diffraction patterns do not overlap. independent of the width of the slit. if the central bright spots of the individual diffraction patterns overlap. independent of the wavelength of the light. A
If you are charging an initially uncharged capacitor in an RC circuit, the voltage of the capacitor
starts at the battery voltage and decreases to zero. remains at zero always. always remains equal to the battery voltage. starts at zero and increases to the battery voltage. D
The rear window defogger on your car works by Joule heating. If the current through those wires doubles, the heating power
stays the same. quadruples. halves. doubles. B
Visible light is the only really useful type of electromagnetic radiation.
False
The units of the time constant are ohm-farad. One ohm-farad equals one second.
True
On average, an electric water heater (4.5 kW) operates for 1.5 hours each day. If the cost of electricity is $0.20/kWh, what is the cost of operating the heater during a 14-day period?
$18.90 $12.60 $40.50 $0.90 A
A small dog sits at a distance of 2.0 m in front of a plane mirror. If the dog jumps away from the mirror with a speed of 0.75 m/s, how fast does the dog recede from its image?
-0.75 m/s. 0.75 m/s. 1.5 m/s. 0 m/s. C
If an object is 20 cm in front of a concave mirror that has a focal length of 80 cm, how tall will the image be?
1.3 times as tall as the object. 1.5 times as tall as the object. As tall as the object. 2.0 times as tall as the object. A
What is the voltage across ten 2.0 V batteries when they are connected in parallel?
10 V 2.0 V 5.0 V 20 V B
A solenoid with 300 turns per centimeter has an iron core with a relative permeability of 100. The solenoid carries a current of 5.0 A. What is the magnetic field at the central axis of the solenoid?
19 T 1.9 T 0.19 T 30 T A
Red light has a wavelength of 650 nm, and that of violet light is 430 nm. What is their frequency difference?
2.36x10^(14) Hz 220 Hz 1.36x10^(6) Hz 1.36x10^(15) Hz A
An AC circuit with a resistance of 10-ohms has an effective current of 3.0 A. Find the peak voltage.
42.4 V 30 V 42.4 0.3 V A
A silver wire is 0.3 m long and has a diameter of 0.05 cm. What is the resistance of the wire?
6.1x10^(-3) ohms 6.1x10^(-7) ohms 2.4x10^(-2) ohms 1.6x10^(-8) ohms C
Two charges, +4.0 micro-C and +3.0 micro-C, are separated by a distance of 35 cm. What is the electric field halfway between the charges?
7.3x10^(4) N/C towards the +3.0 micro-C charge 2.9x10^(5) N/C towards the +3.0 micro-C charge 2.9x10^(5) N/C 2.9x10^(11) N/C towards the +4.0 micro-C charge B
A 200-ohm resistor is placed in a circuit with four identical batteries connected in series. If the resistor draws 4.0 A, what is the terminal voltage of each battery?
75 V 200 V 100 V 1600 V B
A 6.0-volt battery is connected to a parallel plate capacitor with plate areas of 0.3 meters-squared each and a plate separation of 10 mm. How much energy is stored in the capacitor?
8.2x10^(-10) J 4.9x10^(-9) 1.6x10^(-9) J 4.8x10^(-9) J D
An emergency AC generator operates at a rotation frequency of 120 Hz. If the output voltage is zero at t=0, when is it next zero?
8.33x10^(-3) s 4.17x10^(-3) s 3.13x10^(-3) s 1.67x10^(-2) s B
A square loop of wire that encloses an area of 0.20 m^2 is in a uniform magnetic field of 0.10 T. What is the flux through the loop if its plane is at an angle of 62 degrees to the field?
9.4x10^(-3) 9.4x10^(-3) Wb 2.0x10^(-2) Wb 1.8x10^(-2) Wb D
A certain farsighted person has a near point of 75 cm. Which type of lens should an optometrist prescribe to see objects as close as 20 cm?
A diverging lens with power=-3.66 D. A converging lens with power=+6.33 D. A converging lens with power=+3.66 D. A diverging lens with power=-6.33 D. C
In the electric circuit diagram below, possible locations of an ammeter and a voltmeter are indicated by circles 1, 2, 3, and 4. Which of the following statements is true?
A voltmeter at position 3 will measure less than the total voltage of the battery. An ammeter at position 1 will measure the total current provided by the battery An ammeter at position 4 will measure the total current provided by the battery. A voltmeter at position 2 will measure the total voltage of the battery B
With a battery, direct currents can sometimes flow from the anode to the cathode, but at other times they flow in the opposite direction.
False
To get destructive interference with a non-reflective coating on a glass surface, the light has to travel an extra distance in the coating equal to one quarter of a wavelength.
False
The distance between bright fringes on a screen in a two-slit experiment is independent of wavelength.
False
The final image formed by two converging lenses is virtual.
False
The image formed by a plane mirror is formed on the same side of the mirror as the object.
False
The only way for an object to have an electric charge is to have an excess of electrons.
False
ALL rays that are parallel to the optical axis converge at the focal point for a concave spherical mirror.
False
Connecting resistors in series always decreases the total resistance.
False
Diverging lenses correct myopia because they force the light rays to converge in front of the retina.
False
Electric field lines are drawn parallel to equipotentials.
False
For a soap bubble, light reflecting from the inner surface of the bubble undergoes a phase-shift of 180-degrees.
False
If the incident angle is less than the the critical angle, then you will have total internal reflection.
False
If two current-carrying wires are placed parallel to one another, but the currents run in opposite directions, the wires will attract one another.
False
A solid conducting sphere is surrounded by a thick, spherical conducting shell. A total charge of -Q is initially placed and released at the center of the inner sphere. After equilibrium is reached, how much charge is on the outer surface of the shell?
No charge +Q -Q C
Polarizer A is set up so that its polarization direction is vertical. Polarizer B is set up so that its polarization direction is 45 degrees from vertical. Which of the following describes light that has passed through both filters?
No light passes through both polarizers. It is less intense than the original light and is polarized vertically. It is as intense as the original light and is polarized 45 degrees from vertical. It is less intense than the original light and is polarized 45 degrees from vertical. C
Electric fields are vector quantities. Which of the following descriptions is correct?
Positive charges have electric field vectors that point AWAY FROM the charge. Positive charges have electric field vectors that point TOWARDS the charge The sign of the charge has nothing to do with the field direction. Negative charges have electric field vectors that point AWAY FROM the charge A
An object with charge -Q is placed in an electrically neutral metal cup (without touching the cup). Which of the following best describes the situation?
The electric field in the metal of the cup is defined by -Q, the charge in the metal is +Q, and there is no surface charge. The electric field in the metal of the cup is zero, the charge in the metal is -Q, and there is no surface charge. The electric field in the metal of the cup is defined by +Q, the charge in the metal is -Q, and there is no surface charge. The electric field in the metal of the cup is zero, the charge in the metal is zero, and the surface charge is +Q The electric field in the metal of the cup is zero, the charge in the metal is zero, and the surface charge is -Q. D,E
Imagine two sets of charges; set A is made up of two electrons, and set B is made up of two protons. The two sets of charges are far from each other so they cannot affect one another. Which of the following is true?
The electric forces in both cases are attractive. The electric forces in set A are attractive, but the forces in set B are repulsive. The electric forces in set A are repulsive, but the forces in set B are attractive. The electric forces in both cases are repulsive. D
The net force on a current-carrying loop in a uniform magnetic field is zero.
True
Object A has a net charge of +Q. Object B has a net charge of +2Q. A positive test charge is first brought 1 m from object A. Object A is removed and the same test charge is brought 1 m from object B. Which of the following correctly describes the relative magnitudes of the electric fields experienced by the test charge?
The field due to object A is four times that due to object B. The field due to object B is four times that due to object A. The field due to object B is twice that due to object A. The field due to object A is twice that due to object B. C
Imagine two charges A and B. Charge A is drawn with 8 electric field lines coming from its surface. Charge B is drawn with 16 electric field lines coming from its surface. Which of the following is true?
The magnitude of charge B is 4 times as large as charge A. The magnitude of charge A is twice as large as charge B. The magnitude of charge A is 4 times as large as charge B. The magnitude of charge B is twice as large as charge A. D
You rub a balloon on your hair and it gains a net negative charge. Which of the following statements is true?
The negative charge gained by the balloon has been lost by your hair, so the net change in the charge of the hair-balloon system is zero. The negative charge gained by the balloon is equal to the negative charge left on your hair, so the net change in the charge of the hair-balloon system is negative. The charge gained by the balloon was created by induction, so the net change in the charge of the hair-balloon system is negative. The charge gained by the balloon was created by friction, so the net change in the charge of the hair-balloon system is negative. A
How are electric potential difference (voltage) and electric potential energy related?
The potential energy is the voltage per unit positive charge. The voltage is the electric field value divided by a positive charge. There is no relationship. The voltage is the potential energy per unit positive charge. D
The magnetic field due to an induced current points in a direction opposite to the direction of the field that caused the induced current.
True
A ray of light leaves an object and passes through the focal point of a concave spherical mirror. After it reflects from the mirror, which of the following correctly describes its path?
The ray retraces its original path, but moving in the opposite direction. The ray travels parallel to the optical axis. The ray passes through the radius of curvature point. The ray travels perpendicular to the optical axis. B
Two parallel plates are a distance d apart with a constant electric field E between them. An electron with charge q is released from a point near the negative plate and is made to travel at constant velocity. Which of the following is correct?
The work done by the electric field as the charge moves is zero. The work done by the electric field as the charge moves is +qEd. The work done by the electric field as the charge moves is -qEd. B
A step-up transformer increases voltage while at the same time decreasing the current.
True
For a soap bubble, light reflecting from the outer surface of the bubble undergoes a phase shift of 180-degrees.
True
In a Kirchoff loop, if the loop direction and current direction coincide for a resistor, the voltage is considered to be negative.
True
In order to see a rainbow, the sun needs to be at your back.
True
Kirchoff's loop theorem states that the sum of ALL potential differences (drops and sources) around a closed loop must be zero.
True
Negative charges, when allowed to move, go towards regions where the electric potential is high.
True
Rayleigh scattering predicts that the scattering of light is greater for light with short wavelengths.
True
Refraction is due to light propagating at different speeds in different media.
True
The angle of incidence equals the angle of reflection.
True
The angular magnification relates the angular size of an object at some location to the angular size of the image formed by a lens at the same location.
True
How does the index of refraction in water for yellow light compare to that for green light?
Yellow light has a lower index in water compared to green light. Yellow light has a higher index in water compared to green light. All visible light has the same index in water. A
If you place an object at the center of curvature of a spherical mirror, light from the object encounters
a convex mirror. a concave mirror. nothing listed here. a plane mirror. B
An induced EMF can be caused by (choose ALL that apply)
a loop of wire that changes its size in a constant magnetic field. moving a loop of wire along the direction of a constant magnetic field. a loop of wire that changes its size, even if there is no magnetic field present a loop of wire that changes its orientation with respect to a constant magnetic field. a magnetic field that changes in time. A,D,E
According to Ohm's law, a graph of voltage (y-axis) versus resistance (x-axis) would look like
a straight horizontal line (constant value). a straight line with slope equal to the current value. a straight line with slope equal to the inverse of the current value. a straight line with a slope equal to the resistance value. B
The direction of the magnetic force exerted on a charged object is ALWAYS (choose ALL that apply)
along the magnetic field vector (field direction). perpendicular to the magnetic field vector (field direction). perpendicular to the velocity vector (direction of motion). in a direction that makes the velocity and field vectors align. along the velocity vector (direction of motion). B,C
An interference pattern is produced by
any one source of light. at least two coherent sources of light. at least two sources of light. any one source of coherent light. B
Images formed by plane mirrors (choose ALL answers that you think are correct)
appear to be the same distance behind the mirror as the object is in front of the mirror. have the same heights as their associated objects. are inverted are virtual are real A,B,D
When resistors are connected in parallel, the currents through each resistor
are different with the largest current flowing through the largest resistor. are zero in all resistors but one. are different with the largest current flowing through the smallest resistor. are all equal. C
An electrically neutral object (like a balloon)
can be subjected to electric forces due to polarization. can be subjected to electric forces only if it gains a net negative charge. can be subjected to electric forces only if it gains a net positive charge. cannot be subjected to electric forces because it is neutral. A
We can conserve energy by (choose all answers that are correct)
choosing appliances that minimize power consumption. following Dad's advice to "turn off the light when you're not in the room". increasing the efficiency of all of our appliances and electrical devices. using lightbulbs that use less electrical power while producing the same amount of light. All Correct
In order to measure the voltage drop due to a resistor in a circuit, a voltmeter should be
connected in series, or "in-line", with the resistor. connected in parallel, or "across", the resistor. connected to the battery or voltage source. connected only to the wire through which the current leaves the resistor. B
Three resistors with values of 7.5 ohms, 9.0 ohms, and 20 ohms are connected in series in a circuit with a 12-volt battery. What is the current in each resistor?
current in resistor 1=3.5 A, current in resistor 2=3.5 A, current in resistor 3=3.5 A current in resistor 1=1.6 A, current in resistor 2=1.3 A, current in resistor 3=0.6 A current in resistor 1=0.33 A, current in resistor 2=0.33 A, current in resistor 3=0.33 A. current in resistor 1=1.6 A, current in resistor 2=1.6 A, current in resistor 3=1.6 A C
For a fixed screen distance, increasing the width of a single diffraction slit for light of a single wavelength
does not affect the spacing between dark fringes. increases the spacing between dark fringes. decreases the spacing between dark fringes. C
By convention, magnetic field lines
don't tell us anything about the direction of magnetic fields. can either enter or exit N poles and S poles. enter at N poles and exit from S poles. exit from N poles and enter at S poles. D
The velocity selector in a mass spectrometer utilizes
electric and magnetic fields. electric fields only. magnetic fields only. neither electric nor magnetic fields. A
An object placed in front of a convex spherical mirror
forms a real image that is always larger than the object. forms a virtual image that is always smaller than the object. forms a real image that is always smaller than the object. forms a virtual image that is always larger than the object. B
An object placed in front of a convex spherical mirror
forms a virtual image that is always smaller than the object. forms a virtual image that is always larger than the object. forms a real image that is always larger than the object. forms a real image that is always smaller than the object. A
A converging lens
has no fixed focal length. has a fixed focal length, but the sign is not important. has a negative focal length. has a positive focal length. D
An ideal voltmeter
has zero resistance. has infinite resistance. can have any resistance value. B
In order to measure the current passing through a resistor, an ammeter should
have a very large internal resistance have a resistance equal to that of the resistor being measured. be connected in parallel, or "across", the resistor be connected in series, or "in-line", with the resistor D
Ohm's law can be applied to AC circuits
if the voltage and current used are rms values. no matter what voltage and current values you use. if the resistance used is an rms value. as long as you use the average voltage A
The magnetic field at the center of a current carrying loop (choose ALL answers that apply)
increases in magnitude as the radius of the loop increases. points in a direction perpendicular to the plane that contains the loop. points towards the center of the loop. increases in magnitude as the current increases. B,D
Relative to the vacuum value, a dielectric always
increases the capacitance. doubles the capacitance. leaves the capacitance unchanged. decreases the capacitance. A
For a fixed voltage, you can increase the power by
increasing the resistance. not changing the resistance. decreasing the resistance. C
The resistance of something
is a fundamental property of a material. depends only on its resistivity. depends on its resistivity and its geometry. depends only on its geometry. C
The speed of an electromagnetic wave
is different for different frequencies. is constant. is different for different wavelengths. depends on what creates it. B
The total magnification of a compound microscope
is equal to the sum of the magnifications of the objective and eyepiece lenses. is determined only by the objective lens. is determined only by the eyepiece lens. is equal to the product of the magnifications of the objective and eyepiece lenses. D
In a compound microscope, the image formed by the objective lens
is usually very near the focal point of the eyepiece lens. is real and forms at the eye. is usually very near the focal point of the objective lens. is on the same side of the objective as the object. A
For a telescope, the fact that light enters the objective lens parallel to the optical axis
means that the objective image is formed at the focal point of the objective lens. means that the eyepiece image is formed at the focal point of the eyepiece lens. means that the eyepiece image is formed at the focal point of the objective lens. means that the objective image is formed on the same side of the lens as the object. A
Capacitors connected in series... (Choose ALL answers that are correct)
must have the same voltages. act like one capacitor with a capacitance equal to the sum of the individual capacitances. must have the same charges. act like one capacitor with an inverse capacitance equal to the sum of the inverses of the individual capacitances. C,D
The figure shows a ray of light traveling from a medium with index of refraction n1 to a medium with index of refraction n2. Given the labeled angles, which of the following is the correct Snell's Law expression?
n1 sin αα = n2 sin γγ n1 sin ββ = n2 sin γγ n1 sin αα = n2 sin δδ n1 sin ββ = n2 sin δ D
During any complete cycle in which the initial EMF is zero, the EMF of an AC generator becomes zero again at
no time ever. a time equal to three-quarters of the total period. a time equal to one-quarter of the total period. a time equal to one-half of the total period. D
If you place an object at the center of curvature of a spherical mirror, light from the object encounters
nothing listed here. a concave mirror. a plane mirror. a convex mirror. B
If a current flows to the right in a wire that is in a magnetic field that points into your computer screen, the direction of the force on the wire is
out of the screen towards you. into the screen away from you. towards the bottom of the screen. towards the top of the screen. D
The magnetic force on a current-carrying wire is greatest when the current is
perpendicular to the magnetic field direction. parallel to the magnetic field direction. at a 45-degree angle to the magnetic field direction. due to positive charges only. A
In AC circuits, the voltage and current
reach maximum and minimum values at times separated by 3/4 of a cycle. reach maximum and minimum values at times separated by 1/2 of a cycle. reach maximum and minimum values at times separated by 1/4 of a cycle. reach maximum and minimum values at the same points in time. D
The electric and magnetic fields that make up a light wave
reach maximum values at different times but oscillate in perpendicular directions. reach maximum values at the same time but oscillate in perpendicular directions. reach maximum values at the same time and oscillate in the same direction. reach maximum values at different times and oscillate in the same direction. B
The image produced by a diverging lens is always
real and enlarged. real and reduced. virtual and enlarged. virtual and reduced. D
An equipotential surface is
the amount of work done in moving a charge. the same as the direction of the electric field. always perpendicular to a charge distribution. the set of locations where the electric potential is constant. D
White light enters normal to the side of a glass prism. When the light emerges from an different, angled, side of the prism
the blue light exits with a larger refracted angle. the green light exits with a larger refracted angle. all of the colors remain in a single ray, with the same refracted angle. the red light exits with a larger refracted angle. A
When charging a capacitor in an RC circuit, you expect
the current to increase with time. the current to stay constant. the current to decrease with time. C
In a parallel plate situation, the voltage is 60 V. If the electric potential value at the negative plate is 60 V, then
the electric potential value at the positive plate is -60 V. the electric potential value at the positive plate is 120 V. the electric potential value at the positive plate is 0 V. the electric potential value at the positive plate is 60 V. B
The resistance in a conductor like copper increases with length because
the electrons have more opportunity to bounce off of atoms and not participate in the overall flow. they have farther to go without colliding with atoms. the electrons can be absorbed more easily. the electric force decreases with increasing distance. A
In a motor, back EMF increases as
the external magnetic field gets stronger. the armature loop increases its angular speed. the armature loop decreases its angular speed. the current in the loop increases. B
If a light ray leaves water and enters air,
the light's speed decreases and the angle the ray makes with the normal in air is the same as the angle the ray makes with the normal in water. the light's speed increases and the angle the ray makes with the normal in air is larger than the angle the ray makes with the normal in water. the light's speed decreases and the angle the ray makes with the normal in air is larger than the angle the ray makes with the normal in water. the light's speed increases and the angle the ray makes with the normal in air is smaller than the angle the ray makes with the normal in water. B
The torque on a current-carrying loop is maximum when
the magnetic moment is along the magnetic field direction. the magnetic moment is zero. the magnetic moment points in the direction of the current. the magnetic moment is perpendicular to the magnetic field direction. D
If the distance between two equal positive charges doubles,
the magnitude of the electric force decreases by a factor of 4. the magnitude of the electric force decreases by a factor of 2. the magnitude of the electric force increases by a factor of 4. the magnitude of the electric force does not change. A
During one cycle, the average AC voltage is
the maximum voltage minus the minimum voltage. zero. the maximum voltage. one-half the maximum voltage. B
Look at Fig. 19.10(b). If the charge q3 moved closer to charge q1 along the dashed line,
the net force vector would gain an upward vertical component and its horizontal component would decrease. the net force vector would gain an upward vertical component and its horizontal component would increase. the net force vector would gain a downward vertical component and its horizontal component would increase. the net force vector would remain unchanged. B
For human vision, the near point is
the point farthest from the eye at which objects can be seen clearly. also the focal point of the eye. the point closest to the eye at which objects can be seen clearly. the point right at the surface of the eye. C
Sunrises and sunsets appear to be orange-red because light travels through more atmosphere at those times and
the red light gets scattered into our line of sight. the blue light gets scattered away from our line of sight. the blue light gets scattered into our line of sight. the red light gets scattered away from our line of sight. B
Imagine you are boating on a lake during a warm summer day. Your polarized sunglasses dramatically cut down the glare from the lake's surface because
the reflected light is significantly polarized in the horiztonal direction and your sunglasses have vertical polarizer film. the reflected light is significantly polarized in the horiztonal direction and your sunglasses have horizontal polarizer film. the reflected light is significantly polarized in the vertical direction and your sunglasses have horizontal polarizer film. the reflected light is significantly polarized in the vertical direction and your sunglasses have vertical polarizer film. A
In order to "jump start" a dead car battery, the anodes and cathodes of the dead battery and a good battery are connected in parallel with jumper cables. In this situation,
the total voltage available to the dead car is 4 times as large as that of the good battery. the total voltage available to the dead car is twice as large as that of the good battery. the total voltage available to the dead car is half that of the good battery. the total voltage available to the dead car is the same as that of the good battery. D
In the two-slit experiment, a bright interference fringe is produced on a screen when
the two light waves travel distances that are different by any whole (integer) number of half-wavelengths. the two light waves travel distances that are different by any whole (integer) number of wavelengths. the two light waves travel distances that are different by any even number of wavelengths. the two light waves travel the same distance. B
For resistors in parallel,
the voltages across each resistor are equal. the individual voltage drops across the resistors add up to the total voltage. the currents through each resistor are equal. the current only flows through one resistor. A
A light wave travels in a medium with an index of refraction n1. It reflects from the surface of a medium with an index of refraction of n2. If n2 > n1, then
the wave undergoes a 90-degree phase change. the wave undergoes a 360-degree phase change. the wave undergoes a 180-degree phase change. the wave undergoes no phase shift. C
Two identical waves destructively interfere when
the waves move in opposite directions. the troughs of one wave occur at the same location as the troughs of the other the crests of one wave occur at the same location as the troughs of the other. the crests of one wave occur at the same location as the crests of the other. C
If a loop of wire is stretched in a direction perpendicular to the direction of a constant, uniform magnetic field,
then an induced current will run through the loop because the loop encloses a varying number of magnetic field lines. then no induced current will run through the loop because the magnetic field is constant. then an induced current will run through the loop because the magnetic field is constant. then no induced current will run through the loop because the loop encloses a varying number of magnetic field lines. A
Two objects with opposite charges are fixed in place (they cannot move). If the charge on the negative object doubles and the positive object's charge remains the same,
then the force on both charges increases by a factor of 2. only the force on the positive charge increases by a factor of 2. then the force doesn't change because the objects are fixed. only the force on the negative charge increases by a factor of 2. A
If white light is entering a slab of glass with an incident angle of zero relative to the normal,
there will be a dispersion of the reflected light. there will be no dispersion because all wavelengths have zero refraction angles. there is a dispersion of the wavelengths. the light is only reflected from the surface. B
If the charge on a capacitor is doubled, the energy stored in the capacitor is
tripled. quadrupled. unchanged. doubled. B
The focal length of a spherical mirror is equal to
twice the radius of curvature. the radius of curvature. one-half the radius of curvature. one-quarter of the radius of curvature. C
In a closed circuit, the movement of electrons is best described as
very fast straight-line motions in the direction of the current. basically random movement with a slow drift in the direction of the current. very fast straight-line motions in the direction opposing the current. basically random movement with a slow drift in the direction opposing the current. D
A charged object is brought near a neutral electroscope. If the leaves separate,
you know that the object has a net electric charge. you know that the object has a net negative charge. you know that the object has a net positive charge. you know that the object is electrically neutral. A