Photoelectric Effect Quiz

Photoelectric Effect

• The minimum amount of energy required to eject an electron from a metal surface is called the work function.
• Work function is measured in electron volts (eV).
• Work function depends on the nature of the metal.
• Threshold wavelength (λ₀) is the maximum wavelength of light required to cause the photoelectric effect.
• Kinetic energy (K.E.) of emitted electrons is related to the frequency (f) of incident radiation and the work function (Φ) by the equation: K.E. = hf – Φ, where h is Planck's constant.
• Increasing the intensity of the incident light increases the number of emitted electrons, but the kinetic energy of each electron remains unchanged.
• Threshold frequency (f₀) is the minimum frequency of incident radiation required to eject electrons.
• Einstein's photoelectric equation: K.E. = hf – Φ
• The maximum kinetic energy of emitted photoelectrons (K.E.)max is directly proportional to the frequency (f) of incident light and inversely proportional to the wavelength (λ).
• Stopping potential (V₀) is the minimum negative potential required to stop the most energetic photoelectrons from reaching the anode.

Threshold Wavelength

• The maximum wavelength or longest wavelength of incident radiation that can cause the emission of electrons is called the threshold wavelength.
• Threshold wavelength is inversely proportional to the work function
• Equation: λ₀ = hc/Φ, where h is Planck's constant, c is the speed of light.

Threshold Frequency

• The minimum frequency of incident radiation needed to cause the emission of electrons from a metal surface is called the threshold frequency (f₀)
• Equation: f₀ = Φ/h, where Φ is the work function and h is Planck's constant

Einstein's Photoelectric Equation

• Relates the kinetic energy of emitted electrons to the frequency of incident light and the work function of the metal.
• Equation: Kmax = hf - Φ

Stopping Potential

• The minimum negative potential required to stop the most energetic electrons from reaching the anode is called the stopping potential.
• The stopping potential is related to the maximum kinetic energy of the emitted electrons by the equation: eV₀ = Kmax, where e is the elementary charge.

Photoelectric Effect - Summary

• Instantaneous phenomenon
• Selective frequency of radiation needed
• Kinetic energy (K.E) = Energy (E) - Work Function (Φ)
• Photoelectrons are emitted when light strikes a metal surface

Test your knowledge on the photoelectric effect with this quiz, covering key concepts such as work function, threshold wavelength, and Einstein's photoelectric equation. Understand how energy and frequency relate to the emission of electrons from metal surfaces.