Photon Energy and Photoelectric Effect

The video tutorial covers the concept of photon energy, explaining how it is calculated using Planck's constant and the wavelength of light. It introduces the electron volt as a unit of energy and provides examples of calculating photon energy for different wavelengths. The tutorial also explores how many visible photons are emitted by a bulb and describes an experiment to measure Planck's constant using LEDs. Finally, it discusses evidence that electromagnetic radiation comes in packets, using gamma radiation as an example.

What is the formula for the energy of a photon?

• E = qV

• E = mv^2

• E = hf

• E = mc^2

How much energy is equivalent to one electron volt?

• 1.6 x 10^-19 joules

• 3.2 x 10^-19 joules

• 6.6 x 10^-34 joules

• 9.1 x 10^-31 joules

What is the energy of a photon from a red laser with a wavelength of 660 nm?

• 1.6 x 10^-19 joules

• 6.4 x 10^-19 joules

• 3.2 x 10^-19 joules

• 4.8 x 10^-19 joules

What is the work function of zinc in electron volts?

• 5.33 eV

• 4.33 eV

• 3.33 eV

• 2.33 eV

How is the kinetic energy of an emitted electron calculated in the photoelectric effect?

• Dividing the photon energy by the work function

• Subtracting the work function from the photon energy

• Adding the work function to the photon energy

• Multiplying the work function by the photon energy

What is the power of the small bulb discussed in the video?

• 4 watts

• 3 watts

• 2 watts

• 1 watt

How many visible photons does the bulb emit every second if it is 10% efficient?

• 9 x 10^17 photons

• 3 x 10^17 photons

• 6 x 10^17 photons

• 12 x 10^17 photons

What is the purpose of measuring the minimum voltage needed to light LEDs in the experiment?

• To measure Planck's constant

• To determine the wavelength of light

• To find the energy of electrons

• To calculate the speed of light

What happens when gamma radiation is detected by a Geiger counter?

• It produces a continuous hum

• It generates a constant tone

• It emits a steady light

• It creates a series of clicks

What is the relationship between the energy of a photon and the frequency of light?

• Inversely proportional

• Directly proportional

• Exponentially related

• Unrelated