Which equation relates the energy of a photon to its frequency?

• A. E = c / u
• B. E = m c^2
• C. E = h u
• D. E = h / u

Answer: (C)

Verified step by step guidance

1. Recall that the energy of a photon is directly related to its frequency by a fundamental equation in quantum mechanics.
2. Identify the symbols: \(E\) represents the energy of the photon, \(h\) is Planck's constant, and \(\nu\) (nu) is the frequency of the photon.
3. The correct equation that relates energy and frequency is given by \(E = h \nu\), where energy increases linearly with frequency.
4. Other equations listed, such as \(E = \frac{c}{\nu}\) or \(E = \frac{h}{\nu}\), do not correctly represent the relationship between energy and frequency.
5. The famous equation \(E = mc^2\) relates energy to mass, not frequency, so it is not applicable here.