Periscope is based on the reflection of light.

The correct option is A True

Periscope:

1. Periscope is used to see objects that are not in the line of sight.
2. It works on the principle of laws of reflection.
3. A simple periscope uses two mirrors, which are inclined at an angle of ${45}^o$.
4. When light falls on one mirror, it is reflected back. After the reflection of light, it again falls on the other mirror and gets reflected to the observer's eyes.