PHYS 165 MODULE 10 EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2025-
2026
Continuous Variables - Answers have any real value
quantized variable - Answers a variable that has the smallest value and all possible integer
multiple of that smallest value.
Millikan's Oil Drop Experiment - Answers 1909, Robert took two metal plates , a variable electric
power supply and some oil in a spray bottle. The plates were put one on top of the other. A hole
was made on the top plate. Top plate had positive charge and the bottom plate had negative
charge. He sprayed oil through the hole into the space between the plates. He adjusted the
voltage to make the oil droplet reach equilibrium. He calculated the charge of the drop of oil. He
performed the experiment thousands of times.
this experiment proved : the charge of an object is quantized.
Blackbody - Answers an ideal material that absorbs all frequencies of electromagnetic radiation
and emits all frequencies.
it absorbs all frequencies then appears black.
has an inverse proportion between the wavelength and the maximum intensity.
Max Planck's theory - Answers a blackbody is made up of tiny oscillators ( atoms or groups of
atoms) and that the oscillators can only give off energy when their own energy changes by
certain amounts.
Energy given off at a certain frequency - Answers E = h*f
Planck's Constant - Answers h= 6.63 x 10 ^-34 Js
Photon - Answers packet of energy
Energy given off when counting photons - Answers E= n*h*f
The Photoelectric Effect - Answers Discovered by Heinrich Hertz in 1887.
under the right conditions, when light shines on certain metals, electrons are ejected from the
metal.
, Photoelectric Effect 1 - Answers an electroscope is negatively charged and when ultraviolet light
is shined on the electroscope it discharges quickly.
The light causes the electroscope to emit the excess electrons.
visible energy does not have enough energy to eject electrons from the metal of the
electroscope.
Photoelectric effect 2 - Answers An apparatus that consists of a variable power supply and an
ammeter, a vacuum tube with two electrodes and a light source. The cathode will become
negatively charged and the anode will become positively charged. The charges will flow in the
circuit until the electrodes have enough charge in them to create the same voltage as the power
supply. The ammeter will not read any current.
Photoelectric effect 3 - Answers under the right conditions , when the light is turned on the
ammeter will read a current. The light will shine on the negative electrode forcing electrons to
be emitted from the cathode to the anode, and will complete the circuit.
Photoelectric effect 4 - Answers As the frequency is increased from 0 , there is no current until a
threshold frequency is reached, at that point, there is a large increase in the amount of current
measured.
As the frequency of the light used is increased , the amount of current stays relatively constant.
Stopping Potential - Answers is the amount of electric potential that cuts off the flow of current
in the photoelectric effect experiment.
Stopping potential analogy ( the swimming pool) - Answers Taking a water droplet from the
surface of the pool will require less energy, than if the droplet is at the bottom of the pool.
pool of water = atom
drop = electron
when an electron is far away from the nucleus it requires less energy to be removed compared
to an electron that is in an orbital closer to the atom.
work function - Answers the minimum amount of energy that is needed to be given to an
2026
Continuous Variables - Answers have any real value
quantized variable - Answers a variable that has the smallest value and all possible integer
multiple of that smallest value.
Millikan's Oil Drop Experiment - Answers 1909, Robert took two metal plates , a variable electric
power supply and some oil in a spray bottle. The plates were put one on top of the other. A hole
was made on the top plate. Top plate had positive charge and the bottom plate had negative
charge. He sprayed oil through the hole into the space between the plates. He adjusted the
voltage to make the oil droplet reach equilibrium. He calculated the charge of the drop of oil. He
performed the experiment thousands of times.
this experiment proved : the charge of an object is quantized.
Blackbody - Answers an ideal material that absorbs all frequencies of electromagnetic radiation
and emits all frequencies.
it absorbs all frequencies then appears black.
has an inverse proportion between the wavelength and the maximum intensity.
Max Planck's theory - Answers a blackbody is made up of tiny oscillators ( atoms or groups of
atoms) and that the oscillators can only give off energy when their own energy changes by
certain amounts.
Energy given off at a certain frequency - Answers E = h*f
Planck's Constant - Answers h= 6.63 x 10 ^-34 Js
Photon - Answers packet of energy
Energy given off when counting photons - Answers E= n*h*f
The Photoelectric Effect - Answers Discovered by Heinrich Hertz in 1887.
under the right conditions, when light shines on certain metals, electrons are ejected from the
metal.
, Photoelectric Effect 1 - Answers an electroscope is negatively charged and when ultraviolet light
is shined on the electroscope it discharges quickly.
The light causes the electroscope to emit the excess electrons.
visible energy does not have enough energy to eject electrons from the metal of the
electroscope.
Photoelectric effect 2 - Answers An apparatus that consists of a variable power supply and an
ammeter, a vacuum tube with two electrodes and a light source. The cathode will become
negatively charged and the anode will become positively charged. The charges will flow in the
circuit until the electrodes have enough charge in them to create the same voltage as the power
supply. The ammeter will not read any current.
Photoelectric effect 3 - Answers under the right conditions , when the light is turned on the
ammeter will read a current. The light will shine on the negative electrode forcing electrons to
be emitted from the cathode to the anode, and will complete the circuit.
Photoelectric effect 4 - Answers As the frequency is increased from 0 , there is no current until a
threshold frequency is reached, at that point, there is a large increase in the amount of current
measured.
As the frequency of the light used is increased , the amount of current stays relatively constant.
Stopping Potential - Answers is the amount of electric potential that cuts off the flow of current
in the photoelectric effect experiment.
Stopping potential analogy ( the swimming pool) - Answers Taking a water droplet from the
surface of the pool will require less energy, than if the droplet is at the bottom of the pool.
pool of water = atom
drop = electron
when an electron is far away from the nucleus it requires less energy to be removed compared
to an electron that is in an orbital closer to the atom.
work function - Answers the minimum amount of energy that is needed to be given to an
