Photoelectric Effect & X-rays

Understanding the Photoelectric Effect

The photoelectric effect occurs when light shines on a metal surface and ejects electrons from that surface. This phenomenon demonstrates the particle nature of light.

Key Concepts of the Photoelectric Effect

• Threshold Frequency: There is a minimum frequency of light, called the threshold frequency $f_0$, below which no electrons are emitted, regardless of the light's intensity.
• Photon Energy: The energy of a photon is given by $E = hf$, where $h$ is Planck's constant $(6.63 \times 10^{-34} \text{ Js})$ and $f$ is the frequency of the light.
• Einstein’s Photoelectric Equation: The maximum kinetic energy $K_{\text{max}}$ of the ejected electrons is given by: $$K_{\text{max}} = hf - \phi$$ where $\phi$ is the work function of the metal.

 

Production of X-rays

X-rays are produced when high-energy electrons strike a metal target. This process involves converting kinetic energy into electromagnetic radiation.

Structure of X-ray Tubes

• Cathode: Emits electrons when heated.
• Anode: A metal target where X-rays are produced.
• High Voltage: Accelerates electrons towards the anode.