Question

The formula of kinetic mass of photon is

• A. \(\frac{hv}{c}\)
• B. \(\frac{hv}{c^2}\)
• C. \(\frac{hc}{v}\)
• D. \(\frac{c^2}{hv}\)

Hint:

The kinetic mass of a photon is given by \(m = \frac{hv}{c^2}\), where \(h\) is Planck’s constant and \(v\) is the frequency.

Answer 1

The Correct Option is B

Step 1: Kinetic mass of photon.
The kinetic mass \(m\) of a photon can be expressed in terms of its energy \(E\) and speed of light \(c\). According to Einstein’s equation for energy and mass relation: \[ E = mc^2 \] For a photon, its energy is also given by \(E = hv\), where \(h\) is Planck’s constant and \(v\) is the frequency of the photon. Combining these: \[ hv = mc^2 \] Solving for \(m\): \[ m = \frac{hv}{c^2} \]
Step 2: Analyze options.
- (A) \(\frac{hv}{c}\): Incorrect. This does not correctly relate the energy and mass of a photon.
- (B) \(\frac{hv}{c^2}\): Correct. This matches the correct formula for the kinetic mass of a photon.
- (C) \(\frac{hc}{v}\): Incorrect. This is not the correct formula for the kinetic mass.
- (D) \(\frac{c^2}{hv}\): Incorrect. This does not match the formula.
Step 3: Conclusion.
The correct formula for the kinetic mass of a photon is \(\frac{hv}{c^2}\).