Physics

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Photoelectric Effect Calculator.

Calculate photon energy, maximum electron kinetic energy, and stopping potential.

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01

Set your values

Results update as you type.

Photon energy: 0 J

Photon energy

0.000000J
Maximum kinetic energy: 0 J

Maximum kinetic energy

0.000000J
Stopping potential: 2.138385 V

Stopping potential

0.000000V

Results update automatically as you type.

Use Cases

Physics Homework and Exam Prep

Quickly verify calculations for photoelectric effect problems, ensuring correct application of Einstein's equation and understanding of threshold frequency.

Example: Given a light frequency of 5e14 Hz and a work function of 3e-19 J, find the electron's maximum kinetic energy.

Teaching and Demonstrations

Use in classroom settings to illustrate how changing frequency or work function affects electron emission and stopping potential.

Example: Show that increasing frequency increases kinetic energy while increasing work function decreases it.

Frequently Asked Questions

What does the photoelectric effect calculator compute?
It computes the energy of a photon (E = hf), the maximum kinetic energy of emitted electrons (KEmax = hf - work function), and the stopping potential (V0 = KEmax / e) based on the light frequency and the material's work function.
What units should I use for frequency and work function?
Enter the light frequency in hertz (Hz) and the work function in joules (J). The calculator will output photon energy in joules, kinetic energy in joules, and stopping potential in volts.
Why might the calculator show zero or negative kinetic energy?
If the photon energy (hf) is less than the work function, no electrons are emitted. In that case, the maximum kinetic energy is zero (or negative if you subtract), and the stopping potential is zero. This indicates the light frequency is below the threshold frequency.

Tips & Common Mistakes

Tips

  • Ensure the light frequency is in hertz (Hz) and the work function is in joules (J) to get correct results.
  • Remember that the photon energy is directly proportional to frequency; doubling the frequency doubles the photon energy.
  • If the calculated kinetic energy is negative, it means no photoelectrons are emitted; the frequency is below the threshold.
  • Use the stopping potential to find the maximum kinetic energy in electronvolts (eV) by multiplying by the elementary charge.

Common Mistakes to Avoid

  • Forgetting to convert work function from electronvolts to joules; 1 eV = 1.602e-19 J.
  • Using wavelength instead of frequency; the calculator requires frequency in Hz.
  • Ignoring the threshold condition: if photon energy is less than work function, no electrons are emitted, so kinetic energy is zero, not negative.

Last updated: August 13, 2026