ALL FINAL EXAM MCQ's
Which statements about the force on a charged particle placed in a magnetic field are true?
A magnetic force is exerted only if the particle is moving
Which of the following is necessarily true?
A single photon of violet light has more energy than a single photon of red light
Relativistic formulas for time dilation, length contraction, and mass are valid...
For all speeds
Which of the following statements is true regarding how blackbody radiation changes as the temperature of the radiating object increases?
The maximum intensity increases and the peak wavelength decreases
You want to create a spotlight that will shine a bright beam of light with all of the light rays parallel to each other. You have a large concave spherical mirror and a small light- bulb. Where should you place the lightbulb? (a) At the focal point of the mirror. (b) At the radius of curvature of the mirror. (c) At any point, because all rays bouncing off the mirror will be parallel. (d) None of the above; you can't make parallel rays with a concave mirror.
(a) At the focal point of the mirror.
To shoot a swimming fish with an intense light beam from a laser gun, you should aim (a) directly at the image. (b) slightly above the image. (c) slightly below the image
(a) directly at the image.
As an object moves from just outside the focal point of a converging lens to just inside it, the image goes from _____ and _____ to _____ and _____. (a) large; inverted; large; upright. (b) large; upright; large; inverted. (c) small; inverted; small; upright. (d) small; upright; small; inverted.
(a) large; inverted; large; upright.
Suppose you are standing about 3 m in front of a mirror. You can see yourself just from the top of your head to your waist, where the bottom of the mirror cuts off the rest of your image. If you walk one step closer to the mirror (a) you will not be able to see any more of your image. (b) you will be able to see more of your image, below your waist. (c) you will see less of your image, with the cutoff rising to be above your waist.
(a) you will not be able to see any more of your image.
When moonlight strikes the surface of a calm lake, what happens to this light? (a) All of it reflects from the water surface back to the air. (b) Some of it reflects back to the air; some enters the water. (c) All of it enters the water. (d) All of it disappears via absorption by water molecules.
(b) Some of it reflects back to the air; some enters the water.
You cover half of a lens that is forming an image on a screen. Compare what happens when you cover the top half of the lens versus the bottom half. (a) When you cover the top half of the lens, the top half of the image disappears; when you cover the bottom half of the lens, the bottom half of the image disappears. (b) When you cover the top half of the lens, the bottom half of the image disappears; when you cover the bottom half of the lens, the top half of the image disappears. (c) The image becomes half as bright in both cases. (d) Nothing happens in either case. (e) The image disappears in both cases.
(c) The image becomes half as bright in both cases
If you shine a light through an optical fiber, why does it come out the end but not out the sides? (a) It does come out the sides, but this effect is not obvious because the sides are so much longer than the ends. (b) The sides are mirrored, so the light reflects. (c) Total internal reflection makes the light reflect from the sides. (d) The light flows along the length of the fiber, never touching the sides.
(c) Total internal reflection makes the light reflect from the sides.
When you look at a fish in a still stream from the bank, the fish appears shallower than it really is due to refraction. From directly above, it appears (a) deeper than it really is. (b) at its actual depth. (c) shallower than its real depth. (d) It depends on your height above the water.
(c) shallower than its real depth.
When the reflection of an object is seen in a flat mirror, the image is (a) real and upright. (b) real and inverted. (c) virtual and upright. (d) virtual and inverted.
(c) virtual and upright.
A lens can be characterized by its power, which (a) is the same as the magnification. (b) tells how much light the lens can focus. (c) depends on where the object is located. (d) is the reciprocal of the focal length.
(d) is the reciprocal of the focal length.
Which of the following can form an image? (a) A plane mirror. (b) A curved mirror. (c) A lens curved on both sides. (d) A lens curved on only one side. (e) All of the above.
(e) All of the above.
A converging lens, such as a typical magnifying glass, (a) always produces a magnified image (taller than object). (b) always produces an image smaller than the object. (c) always produces an upright image. (d) always produces an inverted image (upside down). (e) None of these statements are true.
(e) None of these statements are true.
Virtual images can be formed by (a) only mirrors. (b) only lenses. (c) only plane mirrors. (d) only curved mirrors or lenses. (e) plane and curved mirrors, and lenses.
(e) plane and curved mirrors, and lenses.
Parallel light rays cross interfaces from medium 1 into medium 2 and then into medium 3 as shown in Fig. 23-51. What can we say about the relative sizes of the indices of refraction of these media? (a)n1 7n2 7n3. (b)n3 7n2 7n1. (c)n2 7n3 7n1. (d)n1 7n3 7n2. (e)n2 7n1 7n3. (f) None of the above.
(e)n2 7n1 7n3.
Which of the following can be thought of as either wave or a particle?
- electron - proton - light
An Earth observer notes that clocks on a passing space-craft run slowly. The person on the spacecraft.....
- feels normal - observes the Earth clocks moving slowly
Indicate which of the following will produce a magnetic field - a magnet - the earth - an electric charge at rest - a moving electric charge - an electric current - the voltage of a battery not connected to anything - an ordinary piece of iron - a piece of any metal
- magnet - earth - moving electric charge - electric current
When a charged particle moves parallel to the direction of a magnetic field, the particle travels in a
- straight line
In Rutherford's experiment, the fact that some alpha particles were deflected at large angles indicates that
- the nucleus was positive - the nucleus was concentrated in a small region of space - most of the atom is empty space
Which of the following will two observers in inertial reference frames always agree on?
- the speed of light - the validity on the laws of physics
If we set the potential energy of an electron and a proton to be zero when they are an infinite distance apart, then the lowest energy a bound electron in a hydrogen atom can have is
-13.6 eV
A 10-V, 1.0-A dc current is run through a step-up transformer that has 10 turns on the input side and 20 turns on the output side. What is the output? (a) 10 V, 0.5 A. (b) 20 V, 0.5 A. (c) 20V, 1A. (d) 10V, 1A. (e) 0V, 0A.
0 V and 0 A
For the flashing of the flashlight in question 2, what time interval is the proper interval time?
0.87 s
Two spaceships, each moving at a speed 0.75c relative to the Earth, are headed directly toward each other. What do occupants of one ship measure the speed of the other ship to be?
0.96c
Spaceships A and B are traveling directly toward each other at a speed 0.5c relative to the Earth, and each has a headlight aimed toward the other ship. What value do technicians on ship B get by measuring the speed of the light emitted by ship A's headlight?
1.0 c
The fictional rocketship Adventure is measured to be 50 m long by the ship's captain inside the rocket. When the rocket moves past a space dock at 0.5c, space-dock personnel measure the rocket ship to be 43.3m long. What is its proper length?
50 m
Which of the following electron transitions between two energy states (n) in the hydrogen atom corresponds to the emission of a photon with the longest wavelength?
8 to 5
Electrons and photons of light are similar in that
All of the above
6. A nonconducting plastic hoop is held in a magnetic field that points out of the page (Fig. 21-54). As the strength of the field increases, (a) an induced emf will be produced that causes a clockwise current. (b) an induced emf will be produced that causes a counterclockwise current. (c) an induced emf will be produced but no current. (d) no induced emf will be produced.
An emf will be produced but no current
If a metal were replaced with a metal with a higher work function, which light would have the best chance of releasing electrons from the metal?
Blue
Two in different inertial reference frames moving relative to each other at nearly the speed of light see the same two events but, using precise equipment, record different time intervals between the two events. Which of the following is true of their measurements?
Both observers are correct
Which of the following can a transformer accomplish? (a) Changing voltage but not current. (b) Changing current but not voltage. (c) Changing power. (d) Changing both current and voltage.
Changing both current and voltage
You are in a spaceship with no windows, radios, or other means to check outside. How could you determine whether your spaceship is at rest or moving at constant velocity?
Give up! You can't tell
A proton enters a uniform magnetic field that is perpendicular to the proton's velocity. What happens to the kinetic energy of the proton?
It stays the same
If the momentum of an electron were doubled, how would its wavelength change?
It would be halved
If there is induced current in Question 18 (see Fig. 21-51), wouldn't that cost energy? Where would that energy come from in case (a)? (a) Induced current doesn't need energy. (b) Energy conservation is violated. (c) There is less kinetic energy. (d) There is more gravitational potential energy.
Less Kinetic Energy
Light has all the following except:
Mass
If a photon of energy E ejects electrons from a metal with kinetic energy KE, then a photon with energy E/2
Might not eject any electrons
The period of a pendulum attached in a spaceship is 2 seconds while the spaceship is parked on Earth. What is the period to an observer on Earth when the spaceship moves at 0.6c with respect to Earth?
More than 2.0 s
A long straight wire carries a current I as shown in Fig. 21-55. A small loop of wire rests in the plane of the page. Which of the following will not induce a current in the loop? (a) Increasing the current in the straight wire. (b)Moving the loop in a direction parallel to the wire. (c) Rotating the loop so that it becomes perpendicular to the plane of the page. (d)Moving the loop farther from the wire without rotating it. (e) Moving the loop farther from the wire while rotating it.
Moving the loop parallel to the wire
When you throw a baseball, its de Broglie wavelength is
Much smaller than the size of an atom's nucleus
You are in a rocket ship going faster and faster. As your speed increases and your velocity gets closer to the speed of light, which of the following do you observe i your frame of reference?
None of the above
Which statements about the force on a charged particle placed due to a magnetic field are not valid?
None of the above, all are valid
Which of the following is the currently accepted model of the atom?
None of the above, quantum mechanical model
Which of the following will not increase a generator's voltage output? (a) Rotating the generator faster. (b) Increasing the area of the coil. (c) Rotating the magnetic field so that it is more closely parallel to the generator's rotation axis. (d) Increasing the magnetic field through the coil.
Rotating the magnetic field so that is more closely parallel to the generators rotation axis.
When you swipe a credit card, the machine sometimes fails to read the card. What can you do differently? (a) Swipe the card more slowly so that the reader has more time to read the magnetic stripe. (b) Swipe the card more quickly so that the induced emf is higher. (c) Swipe the card more quickly so that the induced currents are reduced. (d) Swipe the card more slowly so
Swipe the card more quickly so the induced emf is higher
Which of the following is true about all series ac circuits? (a) The voltage across any circuit element is a maximum when the current is a maximum in that circuit element. (b) The current at any point in the circuit is always the same as the current at any other point in the circuit. (c) The current in the circuit is a maximum when the source ac voltage is a maximum. (d) Resistors, capacitors, and inductors can all change the phase of the current.
The current at any point in the circuit is the same as at any other point.
The ship adventure travels to a star many light-years away, then turns around and returns at the same speed. When it returns to the space dock, who would have aged less; the space dock personnel or the ship's captain?
The ship's captain
Two parallel wires are vertical. The one on the left carries a 10-A current upward. The other carries 5-A current downward. Compare the magnitude of the force that each wire exerts on the other.
The two wires exert the same force on each other
A beam of red light and a beam of blue light have equal intensities, which statement is true?
There are more photons in the red beam
A laptop computer's charger unit converts 120 V from a wall power outlet to the lower voltage required by the laptop. Inside the charger's plastic case is a diode or rectifier (discussed in Chapter 29) that changes ac to dc plus a (a) battery. (b) motor. (c) generator. (d) transformer. (e) transmission line.
Transformer
Which of the following statements about transformers is false? (a) Transformers work using ac current or dc current. (b) If the current in the secondary is higher, the voltage is lower. (c) If the voltage in the secondary is higher, the current is lower. (d) If no flux is lost, the product of the voltage and the current is the same in the primary and secondary coils.
Transformers work using ac current or dc current
When a generator is used to produce electric current, the resulting electric energy originates from which source? (a) The generator's magnetic field. (b)Whatever rotates the generator's axle. (c) The resistance of the generator's coil. (d) Back emf. (e) Empty space.
Whatever rotates the generators axel.
A coil rests in the plane of the page while a magnetic field is directed into the page. A clockwise current is induced (a) when the magnetic field gets stronger. (b) when the size of the coil decreases. (c) when the coil is moved sideways across the page. (d) when the magnetic field is tilted
When a magnetic field is tilted and When the size of the coil decreases
A wire loop moves at constant velocity without rotation through a constant magnetic field. The induced current in the loop will be (a) clockwise. (b) counterclockwise. (c) zero. (d)We need to know the orientation
Zero
The alternating electric current at a wall outlet is most commonly produced by (a) a connection to rechargeable batteries. (b) a rotating coil that is immersed in a magnetic field. (c) accelerating electrons between oppositely charged capacitor plates. (d) using an electric motor. (e) alternately heating and cooling a wire.
a rotating coil that is immersed in a magnetic field
What has greater mass? a) a neutron and a proton that are far from each other (unbound) b) a neutron and a proton that are bound together in a hydrogen (deuterium) nucleus c) both the same
a) A stable nucleus or bound nucleus has less mass than the sum of the masses of its constituent particle
Which of the following is required by the Pauli exclusion principle? a) No electron in an atom can have the same set of quantum numbers as any other electron in that atom. b) Each electron in an atom must have the same n value c) Each electron in an atom must have different ml values d) Only two electrons can be in any particular shell of an atom e) No two electrons in a collection of atoms can have the exact same set of quantum numbers.
a) Pauli's exclusion principle states that no two electrons in an atom can have the same quantum numbers that means it applies to all electrons in the same atom
Technetium 9843TC has a half life of 4.2x10^6 yr. Strontium 9038Sr has a half-life of 28.79 yr. Which statements are true? a) the decay constant of Sr is greater than the decay constant of Tc b) the activity of 100g of Sr is less than the activity of 100g of Tc c) The long half-life of Tc means that it decays by alpha decay d) A Tc atom has a higher probability of decaying in 1 yr than a Sr atom e) 28.79 g of Sr has the same activity as 4.2 x 10^6 g of Tc
a) The decay constant of a nucleus gives the probability of decaying nuclei over a given period and is inversely proportional to the half-life of a radioactive sample and activity of a radioactive sample is more for lesser decay constant
If a beam of electrons is fired through a slit, a) the electrons can be deflected because of their wave properties b) only electrons that hit the edge of the slit are deflected c) electrons can interact with electromagnetic waves in the slit, forming a diffraction pattern. d) the probability of an electron making it through the slit depends on the uncertainty principle
a) The electrons can be deflected because of their wave properties A material particle under can exhibit both wave nature and particle nature, according to de Broglie. The diffraction and interference patterns of electron are explained by the concept of wave theory. Whenever a beam of electrons is fired through a slit, the electrons deflected through the slit because of their wave nature.
A square loop moves to the right from an area where B=0 completely through a region containing a uniform magnetic field directed into the page, and then out to B=0 after point L. A current is induced in the loop (a) only as it passes line J. (d) as it passes line J or line L. (b) only as it passes line K. (e) as it passes all three lines. (c) only as it passes line L.
as it passes line J or L
Radon has a half-life of about 1600 years. The Earth is several billion years old, so why do we still find radon on this planet? a) Ice-age temperatures preserved some of it b) Heavier unstable isotopes decay into it c) it is created in lightning strikes d) It is replenished by cosmic rays e) Its half-life has increased over time f) Its half-life has decreased over time
b) Radon is one of the daughter nuclei in the decay chain of Uranium-238. All of the daughter nuclei in this series exist on Earth today because of the long half-life period (billions of years) of their parent nucleus. Radon that was existed on Earth would have disappeared long ago, but its existence on the Earth shows that it is continually replenished by the decay of heavier isotopes like Uranium-238
A nucleus has a) more energy than its component neutrons and protons have b) less energy than its component neutrons and protons have c) the same energy as its component neutrons and protons have d) more energy than its component neutrons and protons have when the nucleus is at rest but less energy than when it is moving
b) The nucleus has less energy than that of its constituent particles both protons and neutrons, according to Einstein's energy mass relation, since the total mass of a stable nucleus is always less than the sum of the masses of its constituent particles.
The half-life of a radioactive nucleus is a) half the time it takes for the entire substance to decay b) the time it takes for half of the substance to decay c) the same as the decay constant d) both a and b e) all of the above
b) half life of a radioactive nucleus can be defined as the time in which the radioactive substance becomes half of its original quantity to decay
For the electron configuration of Misconceptual Question 1, what orbital quantum numbers do the electron have? a) 0 b) 0 and 1 c) 0 and 1 and 2 d) 0 and 1 and 2 and 3 e) 0 and 1 and 2 and 3 and 4
b) 0 and 1 The orbital quantum number l indicates Sub shell of the electron s=0 p=1 d=2 f=3 Since the atom has only s orbital and p orbital in its electronic configuration, the orbital quantum numbers of a given atom are 0 and 1
An atom has the electron configuration 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 How many electrons does this atom have? a) 15 b)19 c) 30 d) 46
b) 19 The sum of the number of electrons in Sub shell gives the total number of electrons in that atom. n= 2+2+6+2+1
As a proton moves through space, it creates
both an electric field and a magnetic field
After three half lives, what fraction of the original radioactive material is left? a) none b)1/10 c) 1/8 d) 1/4 e) 3/4 f) 7/8
c)
According to the uncertainty principle a) there is always an uncertainty in a measurement of the position of a particle b) there is always an uncertainty in a measurement of the momentum of a particle. c) there is always an uncertainty in a simultaneous measurement of both the position and momentum of a particle d) All of the above
c) Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.
Which of the following is the best paraphrasing of the Heisenberg uncertainty principle? a) Only if you know the exact position of a particle can you know the exact momentum if the particle b) The larger the momentum of a particle, the smaller the position of the particle c) The more precisely you know the position of a particle, the less well you can know the momentum of the particle d) The better you know the position of a particle, the better you can know the momentum of the particle e) How well you can determine the position and momentum of a particle depends on the particle's quantum numbers.
c) Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.
What is meant by the ground state of an atom? a) All the quantum numbers have their lowest values (n=1, l=ml=0) b) All the principle quantum number of the electrons in the outer shell is 1 c) All of the electrons are in the lowest energy state, consistent with the exclusion principle. d) the electrons are in the lowest state allowed by the uncertainty principle
c) All of the electrons are in the lowest energy state, consistent with the exclusion principle The ground state of an atom is the lowest possible energy state and the arrangement of electrons in their respective shells must obey the Pauli's exclusion principle that no two electrons occupy the same energy state.
Which of the following will generally create a more stable nucleus? a) having more nucleons b) having more protons than neutrons c) Having a larger binding energy per nucleon d) Having the same number of electrons as protons e) Having a larger total binding energy
c) larger binding energy per nucleon represents the more stable nucleus. Thus, more amount of binding energy per nucleon will create stable nucleus a incorrect: if you add more number of nucleons, the effectiveness of the strong nuclear force will decrease, so the nucleus becomes less stable b incorrect: if you have more proton than neutron the electromagnetic force between the proton will be too big to be contained in the nucleus. Thus more protons than neutrons will not create a stable nucleus d incorrect: the element will be electrically neutral, but does not affect the stability of its nucleus. Thus, the same number of electron as proton will not create stable nucleus e) The mass has been lost when the nucleons of an atomic nucleus were put together, therefore it will be bigger as the nucleus gains nucleons, however having more number of nucleons can result in less stability.
A material having which decay constant would have the shortest half life? a) 100/sec b) 5/year c) 8/ century d) 10^9/day
d)
Carbon dating is useful only for determining the age of objects less than about ____ years old. a) 4.5 billion b) 1.2 million c) 600,000 d) 60,000 e) 6000
d)
Uranium-238 decays to lead-206 through a series of a) alpha decays b) beta decays c) gamma decays d) some combination of alpha, beta, and gamma
d)
If the half-life of a radioactive sample is 10 years, then it should take ___ years for the sample to decay completely a) 10 b) 20 c) 40 d) cannot be determined
d) In radioactive decay, the number of radioactive nuclei decreases with the time the half life of a radioactive nucleus can be defined as the time required for half the nuclei of a radioactive sample to decay. We cannot determine the exact time for the sample to decay completely, but we can determine only the probabilistic values over a given period.
How does an atom's nucleus stay together and remain stable? a) The attractive gravitational force between the proton and neutrons overcomes the repulsive electrostatic force between the protons b) Having just the right number of neutrons overcomes the electrostatic force between the protons c) a strong covalent bond develops between the neutrons and protons because they are so close to each other d) none of the above
d) The nuclear force is the strongest force among the gravitational force and the electrostatic force. The electrostatic force is stronger than the gravitational force. The nuclear force is the attraction force between the two nucleons inside a nucleus.
Which of the following is not always a property of lasers? a) All of the photons in a laser light have the same phase b) All laser photons have nearly identical frequencies c) Laser light moves as a beam, spreading out very slowly d) Laser light is always brighter than other sources of light e) Lasers depend on an inverted population of atoms where more atoms occupy a higher energy state than some lower energy state
d) Laser light is intense, but not always brighter than other sources of light Laser light is directional and thus, the light moves as a beam and spreads slowly. Laser is a monochromatic source of light. Photons are in phase and thus the frequencies are nearly identical.
Elements of the periodic table are distinguished by a) the number of protons in the nucleus b) the number of neutrons in the nucleus c) the number of electrons in the atom d) Both a and b e) a, b, c
d) both a and b Periodic table is arranged based on the change in atomic number and atomic mass. Atomic number is the number of protons present in an atom of an element. Atomic mass is the number of protons and neutrons in the atom
A current in a wire points into the page as shown at the right. In which direction is the magnetic field at point A?
down
As a radioactive sample decays, a) the half-life increases b) the half-life decreases c) the activity remains the same d) the number of radioactive nuclei increases e) None of the above
e) In radioactive decay, the number of radioactive nuclei decreases. The half-life of a radioactive nucleus can be defined as the time in which the radioactive substance becomes half of its original quantity to decay. The half-life of a particular radioactive sample is constant but its activity, decaying capability, of a nucleus decreases exponentially as it decays.
There are 82 protons in a lead nucleus. Why doesn't the lead nucleus burst apart? a) Coulomb repulsive force doesn't act inside the nucleus b) Gravity overpowers the Coulomb repulsive force inside the nucleus c) The negatively charged neutrons balance the positively charged protons d) Protons lose their positive charge inside the nucleus e) the strong nuclear force holds the nucleus together
e) The repulsion force between the protons in the nucleus increases as the atomic number of an atom increases and this increase in repulsion force ceases the nucleus leading to collapse of the atom. The neutrons in the nucleus reduce the repulsion forces that exist between the protons. If the neutron number is more, the nucleus will get more stability. The stronger the nuclear forces between proton-proton, proton-neutron, and neutron-neutron dominate the repulsion force between proton-proton and hold the nucleus together.
A sample's half life is 1 day. what fraction of the original sample will have decayed after 3 days? a) 1/8 b) 1/4 c) 1/2 d) 3/4 e)7/8 f) all of it
e) 7/8
Under what condition(s) can the exact location and velocity of an electron be measured at the same time? a) The electron is in the ground state of the atom b) The electron is in an excited state of the atom c) The electron is free (not bound to an atom) d) Both (a) and (b) e) Never
e) Never Heisenberg's uncertainty principle states that the position and momentum of a microscopic particle cannot be determined simultaneously. If you know the position or the momentum of a particle accurately, we cannot measure these two observables simultaneously to an arbitrary accuracy. If you know one of these quantities accurately, we can measure uncertainly of the other quantity only.
The Pauli exclusion principle applies to all electrons a) in the same shell, but not electrons in different shells b) in the same container of atoms c) in the same column of the Periodic Table d) in incomplete shells e) in the same atom
e) in the same atom Pauli's exclusion principle states that no two electrons in an atom can have the same quantum numbers that means its it applied to all electrons in the same atom
Which of the following statements is false? The magnetic field of a current-carrying wire...
exists only if the current in the wire is changing
Two loops of wire are moving in the vicinity of a very long straight wire carrying a steady current up. Find the direction of the induced current in each loop. First v is up parallel to current. second loop v is pointing right "3 o'clock"
first loop-zero second loop- clockwise
In which direction is the magnetic field at point b?
left
As rocket ship Adventure passes by the space dock, the ship's captain flashes a flash light at 1.00 s intervals as measured by space-dock personnel. How often does the flashlight flash relative to the captain?
less than 1.0 s, 0.87 seconds
For a charged particle, a constant magnetic field can be used to change
only the direction of the particle's velocity
Two separate but nearby coils are mounted along the same axis. A power supply controls the flow of current in the first coil, and thus the magnetic field it produces. The second coil is connected only to an ammeter. The ammeter will indicate that a current is flowing in the second coil (a) whenever a current flows in the first coil. (b) only when a steady current flows in the first coil. (c) only when the current in the first coil changes. (d) only if the second coil is connected to the power supply by rewiring it to be in series with the first coil.
only when the current in the first coil changed
A wire carries a current directly away from you. Which way do the magnetic field lines produced by this wire point?
they make circles around the wire