Answer
Verified
406.5k+ views
Hint: A simple periscope is an optical device that is used to see objects at a different height level that may not be possible to observe due to obstacles in the way. It works on the principle of simple reflection. Light from the object is reflected by a series of mirrors inclined at a certain angle which allows it to reach the observer bypassing obstacles that may have been present in a straight line path from the object to the observer.
Complete step by step answer:
A simple periscope is an optical device that is used to observe objects that may be at a different height level or have obstacles in the straight line sight of the observer and the object.
A simple periscope works upon the principle of reflection by a mirror. Mirrors are set up such that the angle of incidence of the light ray is ${{45}^{0}}$. Now since, according to the laws of reflection, the angle of incidence is equal to the angle of reflection, the angle of reflection will also be ${{45}^{0}}$. Hence, the light ray will effectively be turned by $\left( {{45}^{0}}+{{45}^{0}}={{90}^{0}} \right)$. Hence, by a series of such ${{90}^{0}}$ turns of light with the help of properly oriented mirrors, the object can be observed by the observer.
This will be clear with the help of the following diagram.
In the above figure, light rays from the object enter the periscope and are turned by ${{90}^{0}}$ by a mirror. A second mirror again turns it back by ${{90}^{0}}$ and the light ray reaches the eye of the observer and hence, the observer is able to observe the object at a different height level.
This concept is used especially in submarines, where periscopes are used to observe objects above the sea level while the submarine itself remains below the water.
Note: Simple periscopes work upon the principle of reflection. However there are some modern complex periscopes that have been developed that use total reflecting or refracting prisms instead of mirrors. Hence, some complex periscopes also rely upon the principle of refraction for their functioning. Other complex periscopes also employ optical fibres that function and carry light using the principle of total internal reflection of light inside a fibre.
Therefore, students must know of these periscopes also. However, in essence, all of them, like simple periscopes, have an element of reflection and are dependent on the principle of reflection for their functioning.
Complete step by step answer:
A simple periscope is an optical device that is used to observe objects that may be at a different height level or have obstacles in the straight line sight of the observer and the object.
A simple periscope works upon the principle of reflection by a mirror. Mirrors are set up such that the angle of incidence of the light ray is ${{45}^{0}}$. Now since, according to the laws of reflection, the angle of incidence is equal to the angle of reflection, the angle of reflection will also be ${{45}^{0}}$. Hence, the light ray will effectively be turned by $\left( {{45}^{0}}+{{45}^{0}}={{90}^{0}} \right)$. Hence, by a series of such ${{90}^{0}}$ turns of light with the help of properly oriented mirrors, the object can be observed by the observer.
This will be clear with the help of the following diagram.
In the above figure, light rays from the object enter the periscope and are turned by ${{90}^{0}}$ by a mirror. A second mirror again turns it back by ${{90}^{0}}$ and the light ray reaches the eye of the observer and hence, the observer is able to observe the object at a different height level.
This concept is used especially in submarines, where periscopes are used to observe objects above the sea level while the submarine itself remains below the water.
Note: Simple periscopes work upon the principle of reflection. However there are some modern complex periscopes that have been developed that use total reflecting or refracting prisms instead of mirrors. Hence, some complex periscopes also rely upon the principle of refraction for their functioning. Other complex periscopes also employ optical fibres that function and carry light using the principle of total internal reflection of light inside a fibre.
Therefore, students must know of these periscopes also. However, in essence, all of them, like simple periscopes, have an element of reflection and are dependent on the principle of reflection for their functioning.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Assertion The resistivity of a semiconductor increases class 13 physics CBSE
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
The branch of science which deals with nature and natural class 10 physics CBSE
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
Trending doubts
Difference Between Plant Cell and Animal Cell
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Fill the blanks with proper collective nouns 1 A of class 10 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Name 10 Living and Non living things class 9 biology CBSE
What organs are located on the left side of your body class 11 biology CBSE
Who gave the slogan Inquillab Zindabad A Bhagat Singh class 10 social science CBSE