Photon Momentum and Effective Mass

This video tutorial explains how to calculate the momentum of a photon using Planck's constant and the wavelength. It derives the formula from the energy-momentum relation, showing that a photon's energy is equal to its momentum times the speed of light. The tutorial provides examples of calculating momentum for photons with different wavelengths, such as red and UV light, and discusses how changes in wavelength affect momentum. Additionally, it covers the concept of effective mass for photons and how it is calculated using the same principles.

What is the formula for calculating the momentum of a photon?

• Momentum = Wavelength divided by Planck's constant

• Momentum = Energy divided by speed of light

• Momentum = Planck's constant divided by wavelength

• Momentum = Planck's constant times frequency

Why is the rest mass of a photon considered to be zero?

• Photons have a very high speed

• Photons have effective mass but no rest mass

• Photons have a constant energy

• Photons are not affected by gravity

How does the momentum of a photon change if its wavelength is halved?

• The momentum doubles

• The momentum becomes zero

• The momentum is halved

• The momentum remains the same

What is the momentum of a photon with a wavelength of 700 nanometers?

• 1.893 x 10^-27 kg·m/s

• 9.466 x 10^-28 kg·m/s

• 4.91 x 10^-36 kg·m/s

• 6.626 x 10^-34 kg·m/s

What happens to the momentum of a photon if its wavelength decreases?

• The momentum decreases

• The momentum increases

• The momentum remains constant

• The momentum becomes zero

What is the effective mass of a photon with a wavelength of 450 nanometers?

• 9.466 x 10^-28 kg

• 1.893 x 10^-27 kg

• 6.626 x 10^-34 kg

• 4.91 x 10^-36 kg

How is the effective mass of a photon calculated?

• Effective mass = Wavelength divided by Planck's constant

• Effective mass = Planck's constant divided by wavelength times speed of light

• Effective mass = Planck's constant divided by wavelength

• Effective mass = Planck's constant times speed of light

What is the relationship between wavelength and effective mass of a photon?

• As wavelength decreases, effective mass becomes zero

• As wavelength increases, effective mass decreases

• Wavelength and effective mass are independent

• As wavelength increases, effective mass increases

Which constant values are used in calculating the effective mass of a photon?

• Speed of light and energy

• Planck's constant and frequency

• Wavelength and frequency

• Planck's constant and speed of light

What happens to the energy of a photon as its wavelength increases?

• The energy remains constant

• The energy becomes zero

• The energy decreases

• The energy increases