Arrange the following electromagnetic waves in the increasing order of their energies.
A. X-rays
B. \( \gamma \)-rays
C. UV rays
D. Ruby laser
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → D, C, A, B
Photon energy is \( E = hc/\lambda \), so the shorter the wavelength, the higher the energy.
D. Ruby laser: red light, \( \lambda \approx 694\,\mathrm{nm} \) (visible)
C. UV rays: about 400 nm down to 10 nm
A. X-rays: about 10 nm down to \( 10^{-3} \) nm
B. \( \gamma \)-rays: below about \( 10^{-3} \) nm
A ruby laser gives visible light, the lowest-energy radiation in the list.
Increasing order of energy: D, C, A, B.