Light Waves and Photons

The electron volt is a measure of

• charge

• velocity

• electric potential

• momentum

• energy

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-1

Which of the following is true about the momentum of photons?

• Photons have no rest mass, so they have no momentum.

• The momentum of a photon is directly proportional to its energy.

• The momentum of a photon is inversely proportional to the square root of its frequency.

• Photons all travel at the speed of light, so they all have the same momentum.

• The momentum of a photon is directly proportional to its wavelength.

Tags

NGSS.HS-PS4-3

Photoelectrons will be ejected from a material surface if?

• The threshold frequency is greater than the photon frequency

• The work function is less than the photon energy

• The intensity of light is high enough

• The wavelength of photon is maximum

Tags

NGSS.HS-PS4-3

A monochromatic light beam with a quantum energy of 9.0 eV is incident upon a photocell. The work function of the photocell is 4.1 eV. What is the maximum kinetic energy of the electron.

• 4.2 eV

• 4.4 eV

• 4.7 eV

• 4.9 eV

Tags

NGSS.HS-PS3-2

NGSS.HS-PS4-3

In an experiment, photoelectric effect is observed in metal A when light with frequency (f ) falls on the metal. If the light frequency used in this experiment is doubled, the photoelectrons

• Will not be ejected

• Will be ejected as observed in the previous

• Will be ejected with greater number of photoelectrons

• Will be ejected with greater kinetic energy

Tags

NGSS.HS-PS4-3

A metal surface is struck with light of λ = 400 nm, releasing a stream of electrons. If the 400 nm light is replaced by λ= 300 nm light of the same intensity, what is the result?

• More electrons are emitted in a given time interval

• Fewer electrons are emitted in a given time interval

• Emitted electrons are more energetic

• Emitted electrons are less energetic

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-3

NGSS.HS-PS4-4

A metal surface is struck with light of λ = 400 nm, releasing a stream of electrons. If the light intensity is increased (without changing λ ), what is the result?

• More electrons are emitted in a given time interval

• Fewer electrons are emitted in a given time interval

• Emitted electrons are more energetic

• Emitted electrons are less energetic

Tags

NGSS.HS-PS4-3

The SI unit of frequency is the __________.

• meter

• second

• hertz

• meter per second

Tags

NGSS.HS-PS4-1

True or False? The wavelength and frequency of all waves are inversely proportional to each other.

• True

• False

Tags

NGSS.HS-PS4-1

Which of the following colors of visible light has the highest frequency?

• Blue

• Green

• Orange

• Red

• Violet

Tags

NGSS.HS-PS4-1