AQA A level PHYSICS - Turning qg qg qg qg qg
points qg
1. WhatStudy online
were theat three
https://quizlet.com/_7sedu0
observations of cathode rays in a discharge
qg
qg
qg
qg qg
qg qg qg qg qg qg qg qg
tube and the conclusion made from each one?: 1. Tube glowed were ray
qg qg qg qg qg qg qg qg qg qg qg qg qg
hit glass - showed particles carried energy
qg qg qg qg qg qg qg
2. Rays were distorted by magnetic field - were negatively charged
qg qg qg qg qg qg qg qg qg
3. Cast a shadow - particles moved in straight lines
qg qg qg qg qg qg qg qg
2. What is thermionic emission?: When a metal is heated, giving the free
qg qg qg qg qg qg qg qg qg qg qg
elec- trons in it enough energy to escape, producing a beam of electrons
qg qg qg qg qg qg qg qg qg qg qg qg qg
3. Describe the arrangement of an electron gun: A metal filament is
qg qg qg qg qg qg qg qg qg qg
heated producing a beam of electrons by thermionic emission. The
qg qg qg qg qg qg qg qg qg qg
electrons are then accelerated through a high voltage towards an anode.
qg qg qg qg qg qg qg qg qg qg qg
Some pass through a small hole in the anode producing a thin beam.
qg qg qg qg qg qg qg qg qg qg qg qg qg
4. Describe and explain Thomson's method to determine the specific
qg qg qg qg qg qg qg qg
charge of an electron (fine beam tube): Glass tube containing gas at a
qg qg qg qg qg qg qg qg qg qg qg qg qg
low pressure with a magnetic field applied across it. Electron gun produced
qg qg qg qg qg qg qg qg qg qg qg qg
beam of electrons into the tube at right angles to the field, so they follow
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
a circular path. Paths could be seen as electrons excited gas atoms causing
qg qg qg qg qg qg qg qg qg qg qg qg qg
them to emit photons. Magnetic force
qg qg qg qg qg qg
= centripetal force, that value of v subbed into eV=1/2mv2
qg qg qg qg qg qg qg qg qg
5. Why was Thomson's measured value of the specific charge of the
qg qg qg qg qg qg qg qg qg qg
electron significant compared to that of a hydrogen ion?: Thomsons
qg qg qg qg qg qg qg qg qg qg
measured value was about 1800 times larger than the hydrogen ions
qg qg qg qg qg qg qg qg qg qg qg
(protons). The mass of a proton is about 1800 times greater than an
qg qg qg qg qg qg qg qg qg qg qg qg qg
electrons, and so it was proven that the magnitudes of the charge on a
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
proton and electron are equal.
qg qg qg qg qg
6. Describe and explain how Millikan's experiment showed the charge
qg qg qg qg qg qg qg qg
of an electron: 1. measure terminal speed of falling droplet at terminal
qg qg qg qg qg qg qg qg qg qg qg qg
speed weight = upthrust.
qg qg qg qg
show equations qg
2. rearrange to find r. r gives you m because density x volume
qg qg qg qg qg qg qg qg qg qg qg
3. large number of measurements multiples of 1.6... so therefore charge is
qg qg qg qg qg qg qg qg qg qg
1.6...
qg
7. What was Newton's theory of light? what was his main argument?:
qg qg qg qg qg qg qg qg qg qg
The 'Corpuscular theory' in which light consists of tiny particles. At the
qg qg qg qg qg qg qg qg qg qg qg qg
time, light was not known to diffract as experiments weren't accurate
qg qg qg qg qg qg qg qg qg qg qg
enough. It was known that particles travel in straight lines and waves
qg qg qg qg qg qg qg qg qg qg qg qg
diffracted, so light must have been made up of particles.
qg qg qg qg qg qg qg qg qg qg
8. How did Newton's theory of light explain refraction?: Newton stated
qg qg qg qg qg qg qg qg qg
that the corpuscles were attracted into transparent materials. Their parallel
qg qg qg qg qg qg qg qg qg qg
velocity was unchanged but their perpendicular velocity increased, so speed
qg qg qg qg qg qg qg qg qg qg
increased, so he stated that light travelled faster in denser materials
qg qg qg qg qg qg qg qg qg qg qg
1 qg/
qg12
, AQA A level PHYSICS - Turning qg qg qg qg qg
points qg
9. HowStudy
did online at https://quizlet.com/_7sedu0
Newton's theory of light explain reflection?: Newton
qg
qg
qg
qg qg
qg qg qg qg qg qg
stated that a force pushed the corpuscles away from surfaces. Their
qg qg qg qg qg qg qg qg qg qg qg
parallel velocity was unchanged but their perpendicular velocity reversed
qg qg qg qg qg qg qg qg qg
direction.
qg
10. What was Huygen's theory of light?: That light travelled as a wave. Each
qg qg qg qg qg qg qg qg qg qg qg qg
point along a wavefront was a source of secondary wavelets that travelled
qg qg qg qg qg qg qg qg qg qg qg qg
forward at the same speed as the wave. The new wavefront was a surface that
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
was tangential to all of the secondary wavelets. He predicted light speed and
qg qg qg qg qg qg qg qg qg qg qg qg qg
wavelength would decrease in denser materials. He also predicted diffraction
qg qg qg qg qg qg qg qg qg qg
and interference. But he wrongly predicted that light was a longitudinal
qg qg qg qg qg qg qg qg qg qg qg
wave
qg
11. Give four reasons why Newton's theory of light was preferred over
qg qg qg qg qg qg qg qg qg qg
Huy- gens: Newton's reputation was stronger due to work on gravity and
qg qg qg qg qg qg qg qg qg qg qg qg
motion, no experimental evidence for diffraction or interference, no
qg qg qg qg qg qg qg qg qg
experimental evidence of how speed of light changes in denser material,
qg qg qg qg qg qg qg qg qg qg qg
fit better with understanding of physics at the time.
qg qg qg qg qg qg qg qg qg
12. Why was Young's doubt slit experiment significant in the
qg qg qg qg qg qg qg qg
qgdevelopment of theories of light, and why were its conclusions not qg qg qg qg qg qg qg qg qg qg
qgimmediately accepted?: - Young's double slit experiment was the first
qg qg qg qg qg qg qg qg qg
experimental evidence of diffraction an interference, so so proved Huygens
qg qg qg qg qg qg qg qg qg qg
theory and disproved newtons theory. Huygens theory still was not accepted
qg qg qg qg qg qg qg qg qg qg qg
unit years late until it was proven that the speed of light decreases in denser
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
materials.
qg
13. Describe Fizeau's experiment for the speed of light and what value
qg qg qg qg qg qg qg qg qg qg
he got (how the equation is derived): Fizeau shone pulses of light that
qg qg qg qg qg qg qg qg qg qg qg qg qg
were reflected by a partially silvered mirror through a cog, and reflected back
qg qg qg qg qg qg qg qg qg qg qg qg qg
by a mirror at a distance away back to an observer. At low rotational speeds
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
the light is transmitted through the gap and reflected back through the same
qg qg qg qg qg qg qg qg qg qg qg qg qg
gap, so, light os seen by the observer. As the rotational speed increases,
qg qg qg qg qg qg qg qg qg qg qg qg qg
there comes a point where the transmitted light passes through a gap and
qg qg qg qg qg qg qg qg qg qg qg qg qg
the reflected light is blocked by the adjacent gap, so cannot be seen by
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
an observer. If the speed is double again, light is seen again
qg qg qg qg qg qg qg qg qg qg qg qg
as it passes through the adjacent gap. A tooth replaces a gap after 1/2nf
qg qg qg qg qg qg qg qg qg qg qg qg qg
seconds (n=number of teeth and f=frequency). D is the distance from the cog
qg qg qg qg qg qg qg qg qg qg qg qg qg q
the far away mirror so 2d/2nf = 4ndf = speed of light. Fizeaus value was
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
3.13x108 ms-1.
qg qg
14. How was Fizeau's experiment significant in the determination of the
qg qg qg qg qg qg qg qg qg
theory of light?: Fizeau used his experiment to measure the speed of light in
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
water. He saw that it was slower in water, disproving Newton's theory and
qg qg qg qg qg qg qg qg qg qg qg qg qg
2 qg/
qg12
points qg
1. WhatStudy online
were theat three
https://quizlet.com/_7sedu0
observations of cathode rays in a discharge
qg
qg
qg
qg qg
qg qg qg qg qg qg qg qg
tube and the conclusion made from each one?: 1. Tube glowed were ray
qg qg qg qg qg qg qg qg qg qg qg qg qg
hit glass - showed particles carried energy
qg qg qg qg qg qg qg
2. Rays were distorted by magnetic field - were negatively charged
qg qg qg qg qg qg qg qg qg
3. Cast a shadow - particles moved in straight lines
qg qg qg qg qg qg qg qg
2. What is thermionic emission?: When a metal is heated, giving the free
qg qg qg qg qg qg qg qg qg qg qg
elec- trons in it enough energy to escape, producing a beam of electrons
qg qg qg qg qg qg qg qg qg qg qg qg qg
3. Describe the arrangement of an electron gun: A metal filament is
qg qg qg qg qg qg qg qg qg qg
heated producing a beam of electrons by thermionic emission. The
qg qg qg qg qg qg qg qg qg qg
electrons are then accelerated through a high voltage towards an anode.
qg qg qg qg qg qg qg qg qg qg qg
Some pass through a small hole in the anode producing a thin beam.
qg qg qg qg qg qg qg qg qg qg qg qg qg
4. Describe and explain Thomson's method to determine the specific
qg qg qg qg qg qg qg qg
charge of an electron (fine beam tube): Glass tube containing gas at a
qg qg qg qg qg qg qg qg qg qg qg qg qg
low pressure with a magnetic field applied across it. Electron gun produced
qg qg qg qg qg qg qg qg qg qg qg qg
beam of electrons into the tube at right angles to the field, so they follow
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
a circular path. Paths could be seen as electrons excited gas atoms causing
qg qg qg qg qg qg qg qg qg qg qg qg qg
them to emit photons. Magnetic force
qg qg qg qg qg qg
= centripetal force, that value of v subbed into eV=1/2mv2
qg qg qg qg qg qg qg qg qg
5. Why was Thomson's measured value of the specific charge of the
qg qg qg qg qg qg qg qg qg qg
electron significant compared to that of a hydrogen ion?: Thomsons
qg qg qg qg qg qg qg qg qg qg
measured value was about 1800 times larger than the hydrogen ions
qg qg qg qg qg qg qg qg qg qg qg
(protons). The mass of a proton is about 1800 times greater than an
qg qg qg qg qg qg qg qg qg qg qg qg qg
electrons, and so it was proven that the magnitudes of the charge on a
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
proton and electron are equal.
qg qg qg qg qg
6. Describe and explain how Millikan's experiment showed the charge
qg qg qg qg qg qg qg qg
of an electron: 1. measure terminal speed of falling droplet at terminal
qg qg qg qg qg qg qg qg qg qg qg qg
speed weight = upthrust.
qg qg qg qg
show equations qg
2. rearrange to find r. r gives you m because density x volume
qg qg qg qg qg qg qg qg qg qg qg
3. large number of measurements multiples of 1.6... so therefore charge is
qg qg qg qg qg qg qg qg qg qg
1.6...
qg
7. What was Newton's theory of light? what was his main argument?:
qg qg qg qg qg qg qg qg qg qg
The 'Corpuscular theory' in which light consists of tiny particles. At the
qg qg qg qg qg qg qg qg qg qg qg qg
time, light was not known to diffract as experiments weren't accurate
qg qg qg qg qg qg qg qg qg qg qg
enough. It was known that particles travel in straight lines and waves
qg qg qg qg qg qg qg qg qg qg qg qg
diffracted, so light must have been made up of particles.
qg qg qg qg qg qg qg qg qg qg
8. How did Newton's theory of light explain refraction?: Newton stated
qg qg qg qg qg qg qg qg qg
that the corpuscles were attracted into transparent materials. Their parallel
qg qg qg qg qg qg qg qg qg qg
velocity was unchanged but their perpendicular velocity increased, so speed
qg qg qg qg qg qg qg qg qg qg
increased, so he stated that light travelled faster in denser materials
qg qg qg qg qg qg qg qg qg qg qg
1 qg/
qg12
, AQA A level PHYSICS - Turning qg qg qg qg qg
points qg
9. HowStudy
did online at https://quizlet.com/_7sedu0
Newton's theory of light explain reflection?: Newton
qg
qg
qg
qg qg
qg qg qg qg qg qg
stated that a force pushed the corpuscles away from surfaces. Their
qg qg qg qg qg qg qg qg qg qg qg
parallel velocity was unchanged but their perpendicular velocity reversed
qg qg qg qg qg qg qg qg qg
direction.
qg
10. What was Huygen's theory of light?: That light travelled as a wave. Each
qg qg qg qg qg qg qg qg qg qg qg qg
point along a wavefront was a source of secondary wavelets that travelled
qg qg qg qg qg qg qg qg qg qg qg qg
forward at the same speed as the wave. The new wavefront was a surface that
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
was tangential to all of the secondary wavelets. He predicted light speed and
qg qg qg qg qg qg qg qg qg qg qg qg qg
wavelength would decrease in denser materials. He also predicted diffraction
qg qg qg qg qg qg qg qg qg qg
and interference. But he wrongly predicted that light was a longitudinal
qg qg qg qg qg qg qg qg qg qg qg
wave
qg
11. Give four reasons why Newton's theory of light was preferred over
qg qg qg qg qg qg qg qg qg qg
Huy- gens: Newton's reputation was stronger due to work on gravity and
qg qg qg qg qg qg qg qg qg qg qg qg
motion, no experimental evidence for diffraction or interference, no
qg qg qg qg qg qg qg qg qg
experimental evidence of how speed of light changes in denser material,
qg qg qg qg qg qg qg qg qg qg qg
fit better with understanding of physics at the time.
qg qg qg qg qg qg qg qg qg
12. Why was Young's doubt slit experiment significant in the
qg qg qg qg qg qg qg qg
qgdevelopment of theories of light, and why were its conclusions not qg qg qg qg qg qg qg qg qg qg
qgimmediately accepted?: - Young's double slit experiment was the first
qg qg qg qg qg qg qg qg qg
experimental evidence of diffraction an interference, so so proved Huygens
qg qg qg qg qg qg qg qg qg qg
theory and disproved newtons theory. Huygens theory still was not accepted
qg qg qg qg qg qg qg qg qg qg qg
unit years late until it was proven that the speed of light decreases in denser
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
materials.
qg
13. Describe Fizeau's experiment for the speed of light and what value
qg qg qg qg qg qg qg qg qg qg
he got (how the equation is derived): Fizeau shone pulses of light that
qg qg qg qg qg qg qg qg qg qg qg qg qg
were reflected by a partially silvered mirror through a cog, and reflected back
qg qg qg qg qg qg qg qg qg qg qg qg qg
by a mirror at a distance away back to an observer. At low rotational speeds
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
the light is transmitted through the gap and reflected back through the same
qg qg qg qg qg qg qg qg qg qg qg qg qg
gap, so, light os seen by the observer. As the rotational speed increases,
qg qg qg qg qg qg qg qg qg qg qg qg qg
there comes a point where the transmitted light passes through a gap and
qg qg qg qg qg qg qg qg qg qg qg qg qg
the reflected light is blocked by the adjacent gap, so cannot be seen by
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
an observer. If the speed is double again, light is seen again
qg qg qg qg qg qg qg qg qg qg qg qg
as it passes through the adjacent gap. A tooth replaces a gap after 1/2nf
qg qg qg qg qg qg qg qg qg qg qg qg qg
seconds (n=number of teeth and f=frequency). D is the distance from the cog
qg qg qg qg qg qg qg qg qg qg qg qg qg q
the far away mirror so 2d/2nf = 4ndf = speed of light. Fizeaus value was
qg qg qg qg qg qg qg qg qg qg qg qg qg qg qg
3.13x108 ms-1.
qg qg
14. How was Fizeau's experiment significant in the determination of the
qg qg qg qg qg qg qg qg qg
theory of light?: Fizeau used his experiment to measure the speed of light in
qg qg qg qg qg qg qg qg qg qg qg qg qg qg
water. He saw that it was slower in water, disproving Newton's theory and
qg qg qg qg qg qg qg qg qg qg qg qg qg
2 qg/
qg12
