Question

Visible light is an electromagnetic wave, but visible light only makes up a small part of the "Electromagnetic Spectrum." Name four other phenomena that are also electromagnetic waves (but are not visible light). For each example:

- Describe how this wave differs from visible light and your other examples.

- Briefly describe an application of this electromagnetic wave.

Answer 1

Visible light has a wavelength range from 400 nm to 700 nm.

1) Radio frequency is a electromagnetic wave but not visible light. Radio frequency are lower frequency than the visible wave and longer wavelength than visible light. We can use radio frequency for signal transmission that visible light can not.

2) Microwave is second lowest frequency in electromagnetic spectrum. Microwave has frequency range between 300 MHz (1 m) and 300 GHz (1 mm). We use microwave oven to cook our food.

3) X-ray lies in the higher frequency range of em spectrum. It's frequency ranging from 30 petahertz to 30 exahertz. As the frequency is higher they are very energetic. We use X-ray in medical imaging.

4) Gamma rays are the highest frequency in em wave. Gamma ray have wavelengths less than 10 picometers. Excited nucleus emits gamma ray, so by studying emitted gamma ray we can measure nuclear structure.