Question

Arrange the following electromagnetic waves in the ascending order of their energies.
A. X-rays
B. UV-rays
C. Infrared rays
D. Microwaves
Choose the correct answer from the options given below:

• A. A, B, C, D
• B. B, C, D, A
• C. D, B, A, C
• D. D, C, B, A

Hint:

Energy rises with frequency. Microwaves have the lowest frequency of the four.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The energy of a photon is \(E = h\nu = hc/\lambda\). So higher frequency means higher energy, and longer wavelength means lower energy.

Step 2: Recall the spectrum order:
In order of increasing frequency the spectrum runs: radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays.

Step 3: Pick the four given waves:
Lowest energy is microwaves (D). Next is infrared (C). Then ultraviolet (B). The highest is X-rays (A).

Step 4: Write the order:
Ascending order of energy is D, C, B, A.

Step 5: Check the options:
Option 1 is the descending order. Option 2 puts X-rays last but misplaces microwaves. Option 3 wrongly puts infrared after X-rays. Option 4 is correct.

Final Answer:
The ascending order is microwaves, infrared, ultraviolet, X-rays. \[ \boxed{D, C, B, A} \]