Periscope

Summary

A periscope is an optical device used to observe surroundings from a lower position without being seen, commonly used in submarines and military trenches. It is constructed with a long tube bent at 90-degree angles, housing two mirrors at 45-degree angles. The top mirror captures and forms an image of an object, which then acts as the object for the second mirror at the lower end. This process allows light to travel through the tube, producing an image visible to the observer. This principle of multiple reflections enables users to safely view their environment without exposing themselves.

Takeaways

• 😀 A periscope is an optical instrument based on the principle of multiple reflections.
• 😀 It allows an observer to view objects from a lower level, commonly used in submarines and trenches.
• 😀 The primary use of a periscope is to observe enemy movements without being seen.
• 😀 A periscope consists of a long tube bent at right angles.
• 😀 Two mirrors are placed at 45° angles inside the periscope, near the openings of the tube.
• 😀 The mirrors are positioned to reflect light from an object to the observer.
• 😀 The upper mirror creates an image of the object, which becomes the object for the lower mirror.
• 😀 The second mirror reflects this image to the observer, allowing them to see it.
• 😀 The working of a periscope can be understood with the help of a ray diagram.
• 😀 Periscopes are essential tools for observation in situations where visibility is limited and secrecy is necessary.

Q & A

What is a periscope?

A periscope is an optical instrument based on the principle of multiple reflections that allows an observer to view objects from a lower level without being seen.

Where were periscopes commonly used?

Periscopes were widely used in submarines and trenches to observe enemy movements while remaining hidden.

What are the main components of a periscope?

A periscope consists of a long tube bent at right angles twice and has two mirrors fixed at 45° near the openings of the tube.

How do the mirrors in a periscope work?

The two mirrors face each other and direct light from the object to the observer. The top mirror forms an image of the object, which becomes the object for the second mirror at the lower end, producing an image seen by the observer.

What role does the upper or top mirror play in a periscope?

The upper or top mirror forms an image of the object, which acts as the object for the second mirror at the lower end.

What is the function of the lower mirror in a periscope?

The lower mirror receives the image formed by the upper mirror and directs it to the observer's eye, allowing them to see the object.

How is light directed through a periscope?

Light from the object enters the tube and is reflected by the mirrors, with each mirror directing the light to the observer's eye.

Why is the angle of the mirrors important in a periscope?

The mirrors are set at an angle of 45° to ensure that the light is properly reflected through the tube and directed towards the observer.

What is the main principle behind the functioning of a periscope?

The main principle is the use of multiple reflections to transmit an image from one end of the tube to the other.

What role does the ray diagram play in understanding how a periscope works?

A ray diagram helps illustrate and understand how light travels through the periscope, showing how it reflects off the mirrors to reach the observer's eye.