PHYS 165 MODULE 10 EXAM QUESTIONS AND
ANSWERS 2026 COMPLETE STUDY GUIDE
◉ quantized variable. Answer: a variable that has the smallest value
and all possible integer multiple of that smallest value.
◉ Millikan's Oil Drop Experiment. Answer: 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. Answer: 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. Answer: 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. Answer: E = h*f
◉ Planck's Constant. Answer: h= 6.63 x 10 ^-34 Js
◉ Photon. Answer: packet of energy
◉ Energy given off when counting photons. Answer: E= n*h*f
◉ The Photoelectric Effect. Answer: 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. Answer: 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. Answer: 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. Answer: 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. Answer: 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.
ANSWERS 2026 COMPLETE STUDY GUIDE
◉ quantized variable. Answer: a variable that has the smallest value
and all possible integer multiple of that smallest value.
◉ Millikan's Oil Drop Experiment. Answer: 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. Answer: 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. Answer: 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. Answer: E = h*f
◉ Planck's Constant. Answer: h= 6.63 x 10 ^-34 Js
◉ Photon. Answer: packet of energy
◉ Energy given off when counting photons. Answer: E= n*h*f
◉ The Photoelectric Effect. Answer: 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. Answer: 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. Answer: 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. Answer: 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. Answer: 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.
