Photoelectric Effect/ Compton Scattering

Question 1

Describe photoelectric effect experiement

Answer 1

• P.D across anode and cathode in vacuum
• Monochromatic light hits cathode
• Electrons are emitted from cathode
• Electrons are accelerated towards anode

Question 2

Observations of Photoelectric effect

Answer 2

• Max KE does not depend on intensity
• Max KE depends on frequency of light
• No emitted electrons below threshold frequency

Question 3

Compton Scattering definition

Answer 3

• Photon collides with electron
• Photon scatters with less energy

Question 4

Compton scattering equation

Answer 4

λ’-λ = h/mc x cos(1-cosθ)

Question 5

Compton Scattering Classical vs Quantum

Answer 5

• Classical says scattered photon should have same frequency as incident photon
• Scattered photon has less frequency than initial photon