Periscope - Meaning, Working, Uses, FAQs

INTRODUCTION:
Periscope meaning is an optical device, which enables an observer to view the surrounding objects from a lower level. A periscope works on the principle of simple reflection. Periscopes were widely used in submarines and trenches to observe enemy movements without being seen. Periscope meaning in Hindi is पेरिस्कोप and periscope meaning in Tamil is பெரிஸ்கோப். In this article we will study in detail about what is periscope, uses of periscope, how to make a periscope, how does a periscope work.

What is Periscope?

Let us look at a very simple device which is a periscope and define periscope. First of all let us know, who invented periscope? Hippolyte Marie-Davy invented periscope in 1854. It is made by using two mirrors known as periscope mirror. Now let us look which type of mirror are used in periscope? Mirror used in periscope is plane mirror. These two mirrors are placed at an angle of 45 degree angle facing each other inside a tube. They are arranged in such way that when the light comes in from the top mirror, there the light is reflected straight to the bottom mirror. From the bottom mirror the light is reflected straight outside where an observer can see it. So the periscope help us to see an object which are obstructed by direct vision.

So if an object is over the wall or it is inside a window, we are not able to see it. We can use the periscope to sort of peek inside. We will get a view which would normally not get by naked eyes. This periscope has several applications. One of the application is actually in submarine. Submarine travel inside the water, when we have to see things which are above the surface of water. A Periscope allow us to see outside the water while still being inside. So we use the periscope in many ways.

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Construction:

Let us look at how periscope is constructed.

It consist of a long tube bent at right angle twice shown in the figure. Two mirrors fixed in the tube at an angle of 45° near the two openings of the tube. Two mirrors are facing each and they direct the light from the object to the observer. Introduce both of the flat mirrors into the periscope inspecting tube. The mirrors must be fronting each other. When the mirrors are introduced appropriately, each mirror will be relaxing on the wooden supports. As each mirror is introduced, place a small piece of Foil tape over the mirror apertures on the outside of the inspecting tube. Grasp the periscope so the mirrors are resting on the woody support, then look over it.

Working of periscope:

Now how does a periscope work? Periscope working principle is simple reflection.

The upper or top mirror forms an image of the object. This mage acts as an object for the second mirror at the lower end and produces an Image which is seen by the observer. Let us now understand the working of the periscope with the help of ray diagram. Two parallel mirrors A and B are fixed at the bends of the tube faring each other and are at 45° to the frame work. Ray of light entering through the upper aperture strike the mirror A at angle of incidence equal to 45°. This ray gets reflected along the axis of the tube striking the mirror B at an angle 45°. From mirror B, this ray gets reflected parallel to the original path reaching the eyes of the observer. This process repeats itself again and again. This permits us to look over an items or people from round a corner, or from an advanced vantage point than normal.

How we can make periscope at home?

Material we will need:

• Huge cornflakes box or an A4 size or bigger piece of wooden board.
• Adhesive stick or Covering tape.
• Skill knife / Scissors.
• Paint for trimming (Optional).
• 2 mirrors of measurement of 5cm by 5cm or use aluminium foil.
• Periscope outline

NCERT Physics Notes:

• NCERT Notes Class 11th Physics
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Making of a simple periscope:

• Print off the Periscope outline and paste it onto the wooden board.
• When the glue has dried out, cautiously cut out the outline along the solid lines. Be cautious not to cut off the end flaps.
• By the use of the ruler as a guide, ask a grown-up to score down the dotted lines with the craft knife.
• Fold all of the counted lines inwards. Foldaway over the ruler will help you keep the folds straight.
• Fold the periscope over to create a tube, superglue and secure with masking tape if needed.
• Glue the flaps at the finish of the periscope down.
• Paste and insert a mirror into each initials of the periscope.
• The boundaries of the periscope can sometimes end up looking a bit untidy in the places where you scored it. You can arranged them up with a little covering tape if you like.
• It’s a good idea to paint your periscope with a neutral colour or something that will balance with its backgrounds. So if you’re utilising it in the garden, you may need to coat it with green colour.
• For the ultimate secret stakeout, you may want to consider camouflaging your periscope with a little of the thing it surrounds, if you’re outside think about pasting some leaves or stems to it.

Also read :

• NCERT notes Class 10 Science Chapter 10 - Light Reflection and Refraction
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What is the use of periscope?

A periscope allows you to see objects or people in a normal way from a corner or from an advanced point. Periscopes were often used in submarines and trenches to observe enemy movement without being seen. While submarines and other technology vehicles in use today generally use a more complex system of prisms and lenses, the simple mirror periscope described above is easy to make at home and provides a clear and reasonable image that will last well into the world of twentieth century.

Conclusion:

From now on we can conclude that a periscope is an instrument that uses a system of prisms, lenses or mirrors to reflect images through a cylindrical tube. Light from a distant object hits the upper mirror and is then reflected at a 90-degree angle through the cylindrical tube of the periscope. At the bottom line of the periscope, light hits the other mirror and then reflects back to the viewer's eye. This simple periscope uses only flat mirrors like the periscopes used in submarines, which are generally a complex optical system with lenses and mirrors.

Also check-

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