Answer the following questions by selecting the correct/most appropriate options.


X is a device which is used to see around corners and is based on the principle of Y. X and Y respectively are:

Correct option is B

The answer is (b) Periscope, reflection.
Periscope: This is a device with mirrors that allows you to see over obstacles or around corners.
Reflection: Periscopes use mirrors to reflect light, bending its path so you can see an indirect view.
Therefore, a periscope operates on the principle of reflection.
Kaleidoscope: This uses mirrors to create beautiful, symmetrical patterns, but it doesn't help see around corners.
Refraction: This is the bending of light as it travels through different mediums (like water or glass). Telescopes use refraction, but not periscopes.
Dispersion: This is the separation of light into its constituent colors. It's not relevant to the function of a periscope.