- It's the range of frequencies over which electromagnetic radiation is transmitted.
- A spectrum is not a physical object it comes from the latin “spect”, meaning to see or visualize.
- The Electromagnetic radiations are a form of energy which are emitted and absorbed by the charged particles.
- The Electromagnetic spectrum categorizes waves with different frequencies and wavelength according to their wave characteristics, uses and applications.
All wireless communications signals travel over the air via radio and micro frequencies.
Audible Frequency :
| Species | Approximate Range (HZ) |
| Elephant | 16 - 12,000 |
| Gold Fish | 20 - 3,000 |
| Human | 20 - 20,000 |
| Cow | 23 - 35,000 |
| Cat | 45 - 64,000 |
| Pig | 54 - 50,000 |
| Horse | 55 - 33,500 |
| Dog | 67 - 45,000 |
| Porpoise | 75 - 1,50,000 |
| Frog | 100 - 30,000 |
| Sheep | 100 - 30,000 |
| Chicken | 125 - 2,000 |
| Owl | 200 - 12,000 |
| Rat | 200 - 76,000 |
| Rabbit | 360 - 42,000 |
| Mouse | 1,000 - 91,000 |
| Whale | 1,000 - 1,23,000 |
| Bat | 2,000 - 1,10,000 |