Question

The wavelengths of two photons are 2000Å and 4000Å, respectively. What is the ratio of their energies?

• A. \( \frac{1}{4} \)
• B. 4
• C. \( \frac{1}{2} \)
• D. 2

Hint:

The energy of a photon is inversely proportional to its wavelength.

Answer 1

The Correct Option is B

The energy of a photon is inversely proportional to its wavelength, given by: \[ E = \frac{hc}{\lambda} \] Since the wavelength of the second photon is twice that of the first, the energy ratio is \( E_1/E_2 = (4000/2000) = 2 \), so the energy ratio is 4.
Final Answer: \[ \boxed{4} \]