Arrange the following electromagnetic waves in decreasing order of their wavelength respectively.
A. Gamma Rays
B. UV Rays
C. Infrared Rays
D. X-Rays
E. Microwaves
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → E>C>B>D>A
In the electromagnetic spectrum the waves are arranged by wavelength, and wavelength decreases as frequency increases. From the longest wavelength to the shortest the order is radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays.
Microwaves (E) > Infrared Rays (C) > UV Rays (B) > X-Rays (D) > Gamma Rays (A)
NCERT (2026-27):
Gamma Rays – “… Table 8.1 summarises different types of electromagnetic waves, their production and detections. As mentioned earlier, the demarcation between different regions is not sharp and there are overlaps.”
| Type | Wavelength range | Production | Detection |
|---|---|---|---|
| Radio | > 0.1 m | Rapid acceleration and decelerations of electrons in aerials | Receiver’s aerials |
| Microwave | 0.1m to 1 mm | Klystron valve or magnetron valve | Point contact diodes |
| Infra-red | 1mm to 700 nm | Vibration of atoms and molecules | Thermopiles Bolometer, Infrared photographic film |
| Light | 700 nm to 400 nm | Electrons in atoms emit light when they move from one energy level to a lower energy level | The eye Photocells Photographic film |
| Ultraviolet | 400 nm to 1nm | Inner shell electrons in atoms moving from one energy level to a lower level | Photocells Photographic film |
| X-rays | 1nm to 10-3 nm | X-ray tubes or inner shell electrons | Photographic film Geiger tubes Ionisation chamber |
| Gamma rays | <10-3 nm | Radioactive decay of the nucleus | -do- |