Q. Arrange the following electromagnetic radiations in decreasing order of their frequencies.
1. Gamma rays
2. Ultraviolet rays
3. Radio waves
4. X-rays
Select the correct answer from the code given below:
a) 1, 4, 3, 2
b) 4, 1, 2, 3
c) 1, 4, 2, 3
d) 4, 1, 3, 2
Correct Answer: c) 1, 4, 2, 3
Question from UPPSC Prelims 2025
Explanation:
Decreasing frequency means from highest to lowest. In the electromagnetic spectrum: Gamma rays > X-rays > Ultraviolet > Radio waves (since frequency is inversely proportional to wavelength and gamma rays have the shortest wavelengths while radio waves have the longest). Hence the correct order among the given is 1 (Gamma), 4 (X-ray), 2 (UV), 3 (Radio).
