TESU PHYSICS 116 FINAL EXAM | QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS | LATEST EXAM
Problems for classical physics - CORRECT ANSWER - Speed of light does
NOT depend on observer's state of motion, failure of classical electromagnetism
and thermodynamics to account for Black Body Radiation, spectral signatures
of atoms, x-rays and radioactivity, origins of periodic table,
Wave Features - CORRECT ANSWER - Extended in space, scatter in all
directions, can exhibit interference, can exhibit diffraction, carry energy, spread
out
Particle Features - CORRECT ANSWER - Localized in space, have collisions,
don't exhibit interference, don't exhibit diffraction, carry energy, travel in
straight lines
What do we know about light? - CORRECT ANSWER - Electromagnetic
wave, polarize, mostly travels in straight lines, refracts when passing between
media with different index of refraction
How do we know light is a wave? - CORRECT ANSWER - Interference (two
waves can add together and cancel) and diffraction (waves can travel around
corners)
Young's Double Slit Experiment - CORRECT ANSWER - Showed that light
has a wave nature (series of alternating bright and dark bands on screen)
,The "Ultraviolet Catastrophe" - CORRECT ANSWER - Classical
electromagnetic/thermodynamic theory predicted blackbody would blow up at
short wavelengths (wrong)
Planck's Constant - CORRECT ANSWER - "h" - An oscillator can only have
certain energy levels associated with it, sets scale for quantum mechanics.
Photoelectric Effect - CORRECT ANSWER - Observes photons behaving as
particles, (light shining on a metal can eject electrons). The production of
electrons or other free carriers when light is shone onto a material.
Einstein's Explanation of the Photoelectric Effect - CORRECT ANSWER -
Light waves are made up of many photons, each photon is a lump of energy
(E=hf), emission of an electron follows absorption of a single photon, more
intense light is just more photons
Explanation of Photon Collision - CORRECT ANSWER - Photon colliding
with an electron at rest should give up some of its energy to the electron. Lower
energy = longer wavelength
Massless Particle's Momentum - CORRECT ANSWER - P=E/c=hf/c=h/λ
Compton Scattering - CORRECT ANSWER - Photons act like particles when
they collide
DeBroglie Wavelength - CORRECT ANSWER - Wavelength for matter: λ=h/p
Electron Double Slit Experiment - CORRECT ANSWER - Electrons can also
behave as waves and collide with each other just like photons
, Wave-Particle Duality - CORRECT ANSWER - Everything can behave as a
wave and a particle. Travel as waves (interfere) and interact as particles (show
up in one spot).
Quantum Mechanics - CORRECT ANSWER - A set of rules (like Newton's
laws and Maxwell's equations) that describes the behavior of matter at small
distances
Heisenberg Uncertainty Principle - CORRECT ANSWER - uncertainty of
position x uncertainty of momentum > h/2π. Cannot know exact wavelength +
position of wave at the same time
Known Properties of Atoms (~1900) - CORRECT ANSWER - Atoms are
small (0.1 nm), stable, contain electrons, must contain positive stuff too,
positive stuff makes up most of the atom's mass, atoms of a given type are
identical, atoms have their unique spectral "fingerprint"
Importance of Rutherford's Experiment - CORRECT ANSWER - Proved that
atoms have a nucleus with electrons surrounding that nucleus
The Atomic Nucleus - CORRECT ANSWER - Contains all the positive charge
and most mass of the atom, surrounded by electrons, very small (10^-14 m)
Why are atoms stable? - CORRECT ANSWER - If we know electron
wavelength, we don't know its position, does not have to accelerate, will not
radiate, can cause stability of atoms
Atomic Spectroscopy - CORRECT ANSWER - Each type of atom has a
unique spectral "fingerprint." Dilute atomic gases (like Hydrogen) emit and
absorb light of very specific frequencies.
VERIFIED AND WELL DETAILED ANSWERS | LATEST EXAM
Problems for classical physics - CORRECT ANSWER - Speed of light does
NOT depend on observer's state of motion, failure of classical electromagnetism
and thermodynamics to account for Black Body Radiation, spectral signatures
of atoms, x-rays and radioactivity, origins of periodic table,
Wave Features - CORRECT ANSWER - Extended in space, scatter in all
directions, can exhibit interference, can exhibit diffraction, carry energy, spread
out
Particle Features - CORRECT ANSWER - Localized in space, have collisions,
don't exhibit interference, don't exhibit diffraction, carry energy, travel in
straight lines
What do we know about light? - CORRECT ANSWER - Electromagnetic
wave, polarize, mostly travels in straight lines, refracts when passing between
media with different index of refraction
How do we know light is a wave? - CORRECT ANSWER - Interference (two
waves can add together and cancel) and diffraction (waves can travel around
corners)
Young's Double Slit Experiment - CORRECT ANSWER - Showed that light
has a wave nature (series of alternating bright and dark bands on screen)
,The "Ultraviolet Catastrophe" - CORRECT ANSWER - Classical
electromagnetic/thermodynamic theory predicted blackbody would blow up at
short wavelengths (wrong)
Planck's Constant - CORRECT ANSWER - "h" - An oscillator can only have
certain energy levels associated with it, sets scale for quantum mechanics.
Photoelectric Effect - CORRECT ANSWER - Observes photons behaving as
particles, (light shining on a metal can eject electrons). The production of
electrons or other free carriers when light is shone onto a material.
Einstein's Explanation of the Photoelectric Effect - CORRECT ANSWER -
Light waves are made up of many photons, each photon is a lump of energy
(E=hf), emission of an electron follows absorption of a single photon, more
intense light is just more photons
Explanation of Photon Collision - CORRECT ANSWER - Photon colliding
with an electron at rest should give up some of its energy to the electron. Lower
energy = longer wavelength
Massless Particle's Momentum - CORRECT ANSWER - P=E/c=hf/c=h/λ
Compton Scattering - CORRECT ANSWER - Photons act like particles when
they collide
DeBroglie Wavelength - CORRECT ANSWER - Wavelength for matter: λ=h/p
Electron Double Slit Experiment - CORRECT ANSWER - Electrons can also
behave as waves and collide with each other just like photons
, Wave-Particle Duality - CORRECT ANSWER - Everything can behave as a
wave and a particle. Travel as waves (interfere) and interact as particles (show
up in one spot).
Quantum Mechanics - CORRECT ANSWER - A set of rules (like Newton's
laws and Maxwell's equations) that describes the behavior of matter at small
distances
Heisenberg Uncertainty Principle - CORRECT ANSWER - uncertainty of
position x uncertainty of momentum > h/2π. Cannot know exact wavelength +
position of wave at the same time
Known Properties of Atoms (~1900) - CORRECT ANSWER - Atoms are
small (0.1 nm), stable, contain electrons, must contain positive stuff too,
positive stuff makes up most of the atom's mass, atoms of a given type are
identical, atoms have their unique spectral "fingerprint"
Importance of Rutherford's Experiment - CORRECT ANSWER - Proved that
atoms have a nucleus with electrons surrounding that nucleus
The Atomic Nucleus - CORRECT ANSWER - Contains all the positive charge
and most mass of the atom, surrounded by electrons, very small (10^-14 m)
Why are atoms stable? - CORRECT ANSWER - If we know electron
wavelength, we don't know its position, does not have to accelerate, will not
radiate, can cause stability of atoms
Atomic Spectroscopy - CORRECT ANSWER - Each type of atom has a
unique spectral "fingerprint." Dilute atomic gases (like Hydrogen) emit and
absorb light of very specific frequencies.
