Enter the Planck’s constant (6.262E-34) and the threshold frequency (hz) into the Calculator. The calculator will evaluate the Energy Threshold. 

Energy Threshold Formula

ET = h * TR


  • ET is the Energy Threshold (Joules)
  • h is the Planck’s constant (6.262E-34)
  • TR is the threshold frequency (hz)

To calculate Energy Threshold, multiply Planck’s constant by the threshold frequency.

How to Calculate Energy Threshold?

The following steps outline how to calculate the Energy Threshold.

  1. First, determine the Planck’s constant (6.262E-34). 
  2. Next, determine the threshold frequency (hz). 
  3. Next, gather the formula from above = ET = h * TR.
  4. Finally, calculate the Energy Threshold.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Planck’s constant (6.262E-34) = 6.26E-34

threshold frequency (hz) = 600


How does the threshold frequency affect the energy threshold?

The threshold frequency is directly proportional to the energy threshold. This means that as the threshold frequency increases, the energy threshold also increases. This relationship is described by the formula ET = h * TR, where ET is the energy threshold, h is Planck’s constant, and TR is the threshold frequency.

Can the energy threshold be negative?

No, the energy threshold cannot be negative because both Planck’s constant and the threshold frequency are always positive values. The energy threshold represents the minimum energy required to trigger a certain process, such as the emission of electrons in the photoelectric effect, and thus cannot be negative.

Why is calculating the energy threshold important?

Calculating the energy threshold is important in various fields of physics and technology, including quantum mechanics, photochemistry, and semiconductor physics. It helps in understanding the energy dynamics of systems at the quantum level and is crucial for the design and analysis of electronic devices, solar cells, and other technologies that rely on the interaction of matter with electromagnetic radiation.