1. What is a Stopping Voltage Calculator?

Definition: This calculator determines the stopping voltage needed to prevent electrons from reaching the anode in the photoelectric effect.

Purpose: It helps physicists and students understand and calculate the relationship between photon energy and electron emission.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V_s \) — Stopping voltage (Volts, V)
• \( h \) — Planck's constant (4.1357 × 10⁻¹⁵ eV·s)
• \( f \) — Photon frequency (Hertz, Hz)
• \( \phi \) — Work function (eV)
• \( e \) — Electron charge (1.602 × 10⁻¹⁹ C)

Explanation: The photon energy (h×f) minus the work function gives the kinetic energy of the emitted electrons, which is then converted to stopping voltage.

3. Importance of Stopping Voltage Calculation

Details: Calculating stopping voltage is essential for understanding the photoelectric effect, designing photoelectric devices, and verifying quantum theory.

4. Using the Calculator

Tips: Enter the photon frequency in Hertz and the work function in electron volts (eV). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the work function?
A: The work function is the minimum energy needed to remove an electron from the surface of a material.

Q2: Why is Planck's constant important?
A: It relates the energy of a photon to its frequency, fundamental in quantum mechanics.

Q3: What's a typical work function value?
A: It varies by material: ~2.5eV for aluminum, ~4.5eV for copper, ~4.7eV for gold.

Q4: How is frequency related to wavelength?
A: Frequency (f) = speed of light (c) / wavelength (λ), where c ≈ 3×10⁸ m/s.

Q5: What if my stopping voltage is negative?
A: This means the photon energy is less than the work function, so no electrons will be emitted.