Physics Test 3
Beats
A series of alternate reinforcements and cancellations produced by the interference of two waves of lsightly different frequency heard as a throbbing effect in sound waves.
The phenomenon of diffraction is closely related to
Interference
Which of these cities has the smallest incidence of cosmic rays?
Singapore
Coceptual model
describes a system.
The underlying physics of an electric motor is that
a current carrying wire experiences force in a magnetic field
Element
a material made of only one kind of atom. Pure gold is an example as it is made of only gold atoms. Used when referring to macroscopic quantities
Physical model
a model that replicates the object at a more convenient scale
The actual speed of electrons drifting along in a common electric circuit is about the speed of
a slow moving snail
Standing wave
a stationary wave pattern formed in a medium when two sets of identical waves pass through the medium in opposite directions
When you increase the number of turns in a coil to induce more voltage, you
do more work to induce greater voltage.
A magnetic force acts most strongly on a current carrying wire when the wire
either or both of these. Carries a vary large current and is perpendicular to the magnetic field
An electric field surrounds all
electric charge, electrons, and protons
Surrounding moving electric charges are______
both of these. electric fields and magnetic fields
The essential physics concept in an electric generator is
faraday's law
When a pair of charged particles are brought twice as close to each other, the force between them becomes ______
four times as strong
When light refracts at an angle when passing from one medium to another, which of the following does not change?
frequency
The pitch of a musical note corresponds to the sound wave's
frequency.
Frequency
how frequently a vibration occurs. Frequency=1/period
Charge polarization is normally produced by
induction
Frequency and period are related, in that they are
inverses of each other.
When magenta is taken out of white light, the color that remains is
none of these
How many electrons are in the third shell of sodium ( atomic number 11)?
one
If you double both the current and the voltage in a circuit the power_______
quadruples
Reflection
the return of a sound wave and echo
In a simple circuit consisting of a single lamp and a single battery, when the current in the lamp is 2A the current in the battery is _____
2A
Consider a transformer with a primary that has 50 turns of wire and a secondary of 250 turns. Based on this information, a 110-V input will produce an output of how many volts?
550 volts.
What is the wave speed for a wave of 2 meters wavelength that has a frequency of 3 hertz?
6 m/s. Correct, for wave speed = frequency x wavelength.
An element found in another galaxy exists as two isotopes. If 80% of the atoms have the atomic mass of 80 amu and the other have 20% have an atomic mass of 82 amu. what is the approximate atomic mass of the element?
80.4 amu
The amount of energy dissipated by a 100-W bulb in a common parallel circuit
All of the above. Depends on how long the bulb is lit, normally 100 joules per second and depends on the voltage supplied to the lamp.
Sound waves have which of these properties?
All of these. Reflection.Refraction.Interference.Capable of producing beats.
Wave interference is characteristic of which type of waves listed below?
All waves.
Series Circuit
An electric circuit with devices connected in such a way that the current is the same in each device
Parallel Circuit
An electric circuit with two or more devices connected in a way that the same voltage acts across each one and any single one completes the circuit independently of all the others.The total current divideds among the parallel circuits. As the number of brances is increased, the resistance of the circuit is decreased.
Alternating current
An electric current that repeatedly reverses its direction. The electric charges vibrate about relatively fixed points. In the us the rate is 60hz
What is a valence electron?
An electron of the outermost occupied shell of an atom.
Which element has chemical properties the most similar to chlorine( chlorine atomic number 17)?
Bromine
Who is credited with discovering electromagnetic induction?
Faraday and Henry.
Resonance in sound is most closely related to which of the following?
Forced vibrations.
Is light a wave or a stream of particles?
Light can be described by both models-it exhibits properties of both a wave or a particle, depending on the experiment. Known as wave-particle duality. The amount of energy in a photon is directly proportional to the frequency of light. E~f
Transparent and opaque materials
Light is transmitted similar to sound. Light incident on matter forces some electrons in matter to vibrate. opaque materials: colored glass is opaque to much of incident white light
Fundamental rule of electric behavior
Like charges repel and opposites attract
Compressions and rarefactions are characteristic of what type of waves?
Longitudinal waves.
Magnetic force
Similar to an electrical force in that a magnet can both attract and repel without touching and the strength ofits interaction depends on the distance between magnets. Magnetic poles give rise to magnetic force
Doppler effect
The change in frequency of wave motion resulting from motion of the sender or the reciever
Quantum
a beam of light consists of zillions of small discrete packets of energy. Each packet is called a quantum
Electric Current
a flow of charged particles. Transports energy from one place to another.
An electric motor best makes use of the fact that on a current-carrying wire in a magnetic field there exists
a force.
A rainbow is a result of light in raindrops that undergoes
all of the above( internal reflection, dispersion, and refraction)
Total internal reflection occurs when light enters
all of these (a diamond.the water drops that produce a rainbow.prism binoculars.)
The loudness of sound is most closely related to its
amplitude
A sonic boom cannot be produced by
an aircraft flying slower than the speed of sound.
When you thrust a bar magnet to and fro into a coil of wire you induce
an alternating current
Atomic Spectrum
an elements fingerprint
Spectroscope
an instrument that separates and spreads light into its component frequencies. Allows analysis of light emitted by elements when they are made to glow-identifies each element by its characteristic pattern. Each element emits a distinctive glow when energized and displays a distinctive spectral pattern, its fingerprint
law of reflection
angle of incidence=angle of reflection
Electrons
are identical, repel electrons of neighboring atoms, and have electrical repulsion that prevents atomic closeness
Average speed of light through different material
as light travels through denser material it slows down
When a light ray passes at an angle from water into air,the ray in the air bends
away from the normal
You could swallow a capsul of germanium, without significaant ill effects. If proton were added to each germanium nucleus, however, you would not want to swallow the capsule because the germanium would
become arsenic
Rainbows are seen from ground when the Sun is normally
behind you as you face the rainbow.
Refraction (light)
bending of light when it passes from one medium to another caused by change in speed of light.
Light has a maximum constant speed in
between the atoms in glass, water, or the atmosphere.
A magnetic field can be found surrounding any
both of these-current-carrying wire. moving electric charge
The vibrations set up in a radio loudspeaker have the same frequencies as the vibrations
both of these. in the electric signal fed to the loudspeaker and that produce the sound you hear
Nucleons
both protons and neutrons. Called this becahse of their location in the atomic nucleus
Are atoms made out of elements or are elements made out of atoms?
elements are made of atoms
k
constant in coulombs law. k=9.0X10^9 N.m^2/C^2
Convex and Concave mirrors
convex mirror(curves outward)-virtual image is smaller and closer to the mirror than object. Concave(curves inward)-virtual image is larger and farther away than the object
When you double the voltage in a simple electric circuit, you double the_____
current
The shell model
cutaway view of shells in the shell model of the atom. How many electrons on each shell; 2, 8, 8,18,18,32,32. Groups are similar in their electron configurations( halogens, noble gases etc)
To say an object has a negative charge is to say it has an excess of what kind of charges?
electrons
A sonic boom is produced by an aircraft when it
flies continuously faster than sound.
Electric Field
force per unit charge. Can be considered an energetic aura surrounding charged objects. About a charged point the field decreases with distance. Between oppositely charged parallel plates the electric field is uniform.
When a fire engine approaches you with its siren blasting away, sound waves passing you have an increased
frequency
Atom
fundamental unit of an element. Used when discussing the submicroscopic. Atoms make up all matter around us. To dat 118 distinct kinds of atoms-98 found in nature and remainder synthesized
In any region of space where a magnetic field is changing in time, there is an
induced electric field, also changing in time.
Beats in sound are the result of wave
interference
Noise canceling devices such as jackhammer earphones make use of sound
interference
The colors seen in a thin film of gasoline on a wet street are produced by
interference
The iridescent colors seen in the pearly luster of the inside of many seashells are due to
interfrerence
To say a substance is electrically polarized is to say that its net charge is
is normally zero with opposite charges on opposite ends.
To say that charge is conserved is to say that charge
is transferred, but never created or destroyed
Electric potential is measured in units of
joules per coulomb, or volts
Transparent materials
materials such as glass and water allow light to pass through with almost no absorption.
In a circuit with two lamps in parallel if the current in one lamp is 2A the current in the battery is _____
more than 2A
When a 134 hz tuning fork and a 144 hz tuning fork struck the beat frequency is
more than 8 hz
The key ingredient in anything magnetic is
moving electric charge.
Electric potential and electric potential energy are
neither of these
The shape of a magnetic field about a current-carrying wire is much the same as the shape of an electric field
none of the above
When light reflects from a smooth surface, it undergoes a change in
none of these
Sound waves cannot be
none of these (reflected absorbed and diminished by interference)
When we say charge is conserved, we mean that charge can be
not created or destroyed
Atomic number
number of protons in each element listed in the periodic table.
Diffuse reflection
occurs when light is incident on a rough surface and reflected in many directions
Refraction
occurs when sound continues through a medium and bends. The bending of a wave either through a non uniform medium or from one medium to another caused by differences in wave speed
To better see an image of your full face in a steamy mirror, the minimum amount of steam to wipe away should be a patch
one-half the height of your face.
A magnetic force acting on a beam of electrons can change
only the direction of the beam
Pitch
our subjective impression about the frequency of sound
List the following atoms in order from increasing atomic size; thallium(ti) germanium(Ge) Tin(Sn) and phosphorus(P)
p, ge, sn,ti
If we lived on a planet where red light was most scattered in the atmosphere, the sky would look
red and the sunsets blue
When white light passes through a prism, green light is bent more than
red light
The redness of a sunrise or sunset is due mostly to light
scattered
The source of all wave motion is
something vibrating.
A common example of a longitudinal wave is
sound
Which of these do not belong in the family of electromagnetic waves?
sound
Which of these is not an application of electromagnetic induction?
sound
Reverberation
sound due to multiple reflections. Re echoed sounds
A transverse wave typifies light, and a longitudinal wave typifies
sound.
Refraction occurs when there is a change in wave
speed
Refracted light that bends away from the normal is light that has
speeded up
The speed of sound varies with
temperature
Electrically polarized
term applied to an atom or molecule in which the charges are aligned so that one side has slight excess of pos charge and the other side has a slight excess of neg charge.
Polarization
the alignment of the transverse electric vectors that make up electromagnetic radiation. Such waves aligned vibrations are said to be polarized.
The source of all magnetism is______
the motion of electrons
How is the atomic number of an element defined?
the number of protons in an elements nucleus
Fourier discovered that periodic waves can be represented by
the summation of a series of simple sine waves.
The slowing of light in transparent materials has to do with
the time for absorption and re-emission of light
Hertz
the unit of frequency
Electromagnetic wave
the vibrating electric and magnetic fiels make up an electromagnetic wave
Wavelength
the wavelength of a wave is the distance from the top of one crest to the top of the next one or equivalently the distance between successive identical parts of the wave.
Atomic mass
total mass of the atom. Listed in periodic table as atomic mass unit. One atomic mass unit is 1.661X 10^-24 g or 1.661X 10^-27 kg. A nucleus with an atomic number of 44 and a mass of 100 must have 56 neutrons.
What statement is correct?
Charge flows in a circuit
Important facts about atoms
1-every atom has a positively charged nucleus surrounded by negatively charged electrons. 2-All electrons are identical(same mass and quantity of neg charge).3-Nucleus composed of protons and neutrons.
What is the power rating of a lamp connected to a 12V source when it carries 2.5 A
30 W p=cXv
How much resistance must a 9-V device have to keep the current about 1 A?
9 ohms
If an atom has 43 electrons, 56 neutrons, and 43 protons what is the approximate atomic mass. What is the name of this element?
99 amu technetium
Transformer
A device for transferring electric power from one coil of wire to another by means of electromagnetic induction. Consists of an input coil of wire and an output coil of wire. primary voltage/number of primary turns=secondary voltage/number of secondary turns.
Compression
A condensed region of the medium through which the longitudinal wave travels
electromagnet
A magnet whose field is produced by an electric current. It is usually in the form of a wire coil with a piece of iron inside the coil.
What is the principle quantum number?
A number that specifies the energy level of an electron.
harmonic
A partial tone that is an integer multiple of the fundamental frequency. the vibration that begins with the fundamental vibrating frequency is the first harmonic twice the fundamental is the second harmonic and so on.
Interference
A property of all types of waves a result of superimposing different waves often of the same wave length
Rarefraction
A rarefied region or a region of lessened pressure of the medium through which a longitudinal wave travels
Longitudinal wave
A wave in which the medium vibrates in a direction parallel to the direction which the wave travels. Sound consists of longitudinal waves.
Transverse wave
A wave in which the medium vibrates in a direction perpendicular to the direction in which the wave travels. Light is considered a transverse wave
How much more mass does a proton have compared to an electron?
About 1800 times as much mass.
The speed of sound is slowest in which of the following mediums?
Air.
Which of these are correct for an electric field?
All of the above. It's a vector quantity, and can be cancelled. It's the altered space surrounding electric charge. It stores electric energy.
Which of these is the same in identical branches of a parallel circuit?
All of the above. Current Voltage and Resistence.
Why does the atomic size of the elements increase as you look down the first group?
Another shell is added for each element as you move down the group.
Conductor
Any material having free charged particles that easily flow through it when an electric force acts on them is called an electric conductor.
Insulator
Any material in which charged particles do not easily flow
Direct Current
Charges flowing in one direction.
Magnetic domain
Clustered regions of aligned magnetic atoms. When these regions themselves are aligned with one another, the substance containing them is a magnet
Coulomb's Law
Electrical force decreases inversely as the square of the distance between charges. F=k q1q2/d^2
Bohrs model
Electrons can lose only specific amounts of energy equivalent to transitions between levels. An atoms reaches the lowest energy level called the ground state, where the electron cant lose more energy and can't
How can a spectroscope help us identify elements?
Elements only emit characteristic frequencies of color, much like a fingerprint
Electric Potential Energy
Energy possessed by the charged pareticle that is due to its location. Electric potential= electric pe/amount of charge. The unit of electric potential is the volt (1 joule/1coulomb)
Electric motor
If we change the design of the galvanometer slightly so that deflection makes a complete turn rather than a partial rotation we have an electric motor.
Quantum Hypothesis
Max Planck german physicist- hypothesized that warm bodies emit radiant energy in discrete bundles called quanta. Energy in each energy bundle is proportional to the frequency of radiation. Einstein stated that light itself is quantize-A beam of light is not a continuous stream of energy but consists of countless small discrete quanta of energy, each quantum called a photon.
Can more than one sound wave exist in the same place at the same time?
Most certainly. Music depends on the superposition of waves.
What is the key ingredient for electromagnetic induction?
Motion. The wire, the field, or the charges have to move for induction to occur.
Can sound travel in a vacuum?
No but light can because light is a vibration of nonmaterial electric and magnetic fields
If you double the frequency of sound, you also double its
None of these.
Consider a wave that travels a distance of 3 meters in 1 second with a frequency of 2 hertz. What is its amplitude?
Not enough information is given.
Generator
Opposite of a motor. converts mechanical energy into electric energy. An electromagnetic device that produces electric current by rotating a coil within a stationary magnetic field
When we consider the time it takes for a pendulum to swing to and fro were talking about the pendulums ______
Period
Ohm's law
The current in a circuit varies in direct proportions to the potential difference or voltage and inversely with the resistance. Current(amperes)=voltage(volts)/resistance(ohms).
What does a frequency of light emitted by an atom correspond to?
The drop of an electron from a higher to lower energy level.
Natural frequency
The frequency at which an elastic object naturally tend to vibrate so that minimum energy is required to produce a forced vibration or to continue vibration at the frequency
Faraday's Law
The law of electromagnetic induction, in which the induced voltage in a coil is proportional to the number of loops multiplied by the rate at which the magnetic field changes within those loops.
Electrical resistance
The property of a material that resists the flow of an electric current through it. Measured in ohms ( Ω)
Electric power
The rate at which work is done. The rate of energy transfer. Power(watts)=current(amperes)Xvoltage(volts)
Ampere
The rate of electric flow is measured in amperes. Rate of flow of 1 coulomb of charge per second.
Magnetic field
The region of magnetic influence around a magnetic pole or a moving charged particle.
What do elements in the same group have in common?
They have similar physical and chemical properties.
Which of the following is not part of the family of electromagnetic radiation?
Wait a minute-all of these are types of electromagnetic radiation.
Wave speed
Wave speed=frequencyXwavelength
The part of the eye in the retina that is most sensitive to color contains mostly
cones
Galvanometer
When an electric current passes through the coil, each loop produces its own effect on the needle so even a very small current can be detected. Such a current indicating instrument is called a galvanometer. Can be calibrated to measure amperes then called an ammeter or calibrated in volts then called a voltameter.
How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?
When an electron wave is confined it is reinforced at only particle frequencies
Resonance
When the frequency of forced vibrations on an object matches the objects natural frequency a dramatic increase in amplitude occurs
Potential difference
Without this there will be no flow of charge. When the ends of an electric conductor are at different electric potentials charges in the conductor flow from higher potential to the lower potential
Atomic excitation
a photon of light is emitted. Electron gains pe and moves further from nucleus and a photon of light is absorbed. Electron loses pe and moves close to nucleus
The visible spectrum occupies
a tiny part of the electromagnetic spectrum
Wave
a wiggle in space and time
Vibration
a wiggle in time
A galvanometer best makes use of the fact that a magnetic field exists
about a current-carrying wire.
Neutrons
accompany protons in the nucleus. Have about the same mass as protons but no charge so are electrically neutral. Both protons and neutrons are nucleons
Protons
carry a positive charge-same quantity of charge as electrons. Proton mass-1800x electron mass. Number of protons in the nucleus=# of electrons surrounding the nucleus of an electrically neutral atom.
Illusions/Mirages
caused by refraction: objects submerged in water appear closer to the surface. Objects such as the sun seen through air are displaced because of atmospheric refraction. Atmospheric refraction is the cause of mirages.
The lowest resistance in a common electric circuit containing a common lamp is in the
connecting wires
The colors on the cover of your physical science book are due to
color subtraction
As more branches are added to a parallel circuit, the overall resistance of the circuit
definitely decreased
Electromagnetic induction
discovered by faraday and henry. Discovered that electric current could be produced in a wire simply by moving a magnet into or out of a coil wire. The induction of voltage when a magnetic field changes with time
Period
each horizontal row is called a period. Across any period the poperties of elements change. For example atomic size tends to decrease as you move from left to right.
Photon
each quantum light is called a pohoton
Group
each vertical colum is called a group. The properties of elements tend to be remarkably similar which is why the elements are said to be grouped.
Light
electromagnetic waves created by vibrating electric charges having frequencies that fall within the range of sight. Frequency of vibrating electrons equals the frequency of the light. Travels nearly a million times faster than sound in air. Light and all electromagnetic waves are transverse wave.
The source of electromagnetic waves is vibrating
electrons
Superconductors
have zero electrical resistance to the flow of charge. Electrons flow without losing energy and without generating heat.
Electron waves
if light can have both wave and particle properties, then what about matter? Louis de Brogilie suggested that elementary particles( electrons) can behave like waves too. This is like how we can see small things under a microscope. Can only see atoms with an electron microscope. Wavelength of atoms much smaller than visible light so need the electron microscope to see it.
An electron beam passing perpendicularly through a magnetic field is deflected. If the beam were instead composed of protons, the beam would be deflected
in the opposite direction.
Electricity and magnetism connect to form
light
Periodic table
listing of all the known elements. Don't need to memorize just learn how to read. The elements are highly organized within the periodic table. Each vertical column is called a group and each horizontal row is called a period
Diffraction is most pronounced for waves that are relatively
long
The vibration along a transverse wave move in a direction
perpendicular to the wave direction
Planetary model of the atom
photons are emitted by atoms as electrons move from higher energy outer levels to lower energy inner levels. The energy of an emitted photon is equal to the difference in energy between two levels.
Would you use a physical model or a conceptual model to describe the following; the brain the mind the solar system or the beginning of the universe.
physical conceptual physical conceptual
What two subatomic particles make up the nucleus?
proton and neutron
Atomic Nucleus
protons and neutrons are bound together to form the atomic nucleus
The number of electrons that move about the nucleus of an electrically neutral atom is the same as the number of
protons in the nucleus
Isotopes
refers to atoms of the same element that contain the same number of protons but different numbers of neutrons in the nucleus. Identified by mass number which is the total number of protons and neutrons in the nucleus. Differ only in mass and not by electric charge therefore isotopes share many characteristics. Total number of neutrons in isotope=mass number-atomic number
Amplitude
refers to the distance from the midpoint to the crest of the wave.
Why aren't atomic masses given in the periodic table whole numbers?
the atomic masses are average atomic masses
Electromagnetic spectrum
the classification of electromagnetic waves according to frequency from radiowaves to gamma rays
Reflection (light)
the returning of a wave to the medium through which it came and when encountering a reflective surface.
Opaque materials
they absorb light without re-emission. Books, desks, chairs and people.
Which are older: the atoms in the body of an elderly person or the atoms in the body of a baby?
they are the same age, which is appreciably older than the solar system
period
time it takes for a complete vibration for a complete cycle. Period=1/frequency
Polarization occurs for waves that are
transverse
The relationship between magnetic force and magnetic pole strength is similar to the relationship between
two of these. force, mass, and distance in Newton's law of gravity. force, charge, and distance in Coulomb's law current, voltage, and resistance in Ohm's law.
Earth's atmosphere is transparent to visible light and opaque to
ultraviolet
Coulomb
unit of charge abbreviated as C. The charge of 1C is the charge associated with 6.25 billion billion electrons.
Touch a 5000-V charged balloon and you're not harmed because, although the energy-charge ratio is high, there is
very little energy on the balloon.
Different colors of light correspond to different
vibrations of electrons in atoms.
A step up transformer in an electric circuit can step up
voltage
Electric current is a flow of electric charge that moves due to an electric pressure called
voltage
The current in a circuit is directly proportional to the impressed
voltage
The function of an electric generator is to produce
voltage and current.
Whether a particular surface acts as a polished reflector or a diffuse reflector depends on the
wavelength of light
When is an object considered to be electrically charged?
when an object has unequal numbers of electrons and protons. More electrons=negatively charged. More protons=positively charged.