Question

Two electromagnetic radiations have wave numbers in the ratio 2 : 3. Their energies per quanta will be in the ratio

• A. 3:2
• B. 9:4
• C. 4:9
• D. 2:3

Answer 1

Answer: (D)

2:3

Answer 2

The energy of a quantum (photon) is given by the formula $E = hc\bar{\nu}$, where $h$ is Planck's constant, $c$ is the speed of light, and $\bar{\nu}$ is the wave number. This implies that energy is directly proportional to the wave number ($E \propto \bar{\nu}$). Therefore, if the ratio of wave numbers of two radiations is $2:3$, the ratio of their energies per quanta will also be $2:3$.