Answer
Verified
402.6k+ views
Hint: To calculate the distance measured by the object measured by an observer from point P we will use the formula: \[{\text{refractive index(}}\mu {\text{) = }}\dfrac{{{\text{Real depth}}\left( H \right)}}{{{\text{Apparent depth}}\left( h \right)}}\]. Where Real depth is the distance object from the surface of a material medium while apparent depth is the distance of image formed due to refraction from the surface of the material medium.
Complete step by step answer:
To find the required distance of the point P we have to draw a schematic diagram
which shows the image of point P formed by the refraction of light phenomenon.
The image of object Q is formed at Q’ by the phenomenon of refraction. So, from the diagram we can have the real depth is OQ and apparent depth is OQ’.
Now for calculating the apparent depth we use the formula :
\[{\text{refractive index(}}\mu {\text{) = }}\dfrac{{{\text{Real depth}}\left( H \right)}}{{{\text{Apparent depth}}\left( h \right)}}\]
We have given that:-
Real depth (OQ) = 3 cm and refractive index(μ) = 1.5
Now substituting the given value in the above expression. we get:
\[
{\text{1}}{\text{.5 = }}\dfrac{{3{\text{ cm}}}}{{{\text{Apparent depth}}\left( {{\text{OQ'}}} \right)}} \\
\Rightarrow {\text{Apparent depth}}\left( {{\text{OQ'}}} \right){\text{ = }}\dfrac{{{\text{3 cm}}}}{{{\text{1}}{\text{.5}}}} \\
\Rightarrow {\text{Apparent depth}}\left( {{\text{OQ'}}} \right){\text{ = 2 cm}} \\
\]
The image of point Q is formed at Q’. So, the observer at point P will see the apparent image at Q’.
Therefore, the required distance from point P is PQ’= PO + OQ’.
Hence, Option (B) is the correct answer.
Note: The formula used for solving this question came from one of the great applications of Snell’s law of refraction for the case of water and air media systems. It is one of the special cases of refraction when an object is placed in a material medium and the observer sees its image from the air medium. So for solving every system of a pair of media the same formula will not be valid. To tackle such kinds of conceptual questions one should have to derive the various formula for refraction phenomenon and also care about the condition for deriving them like:- the angle of incidence and the refraction is very small such that:- \[\tan \theta \approx \theta ,\sin \theta \approx \theta {\text{ and cos}}\theta \approx {\text{1 for very small }}\theta .\]
Complete step by step answer:
To find the required distance of the point P we have to draw a schematic diagram
which shows the image of point P formed by the refraction of light phenomenon.
The image of object Q is formed at Q’ by the phenomenon of refraction. So, from the diagram we can have the real depth is OQ and apparent depth is OQ’.
Now for calculating the apparent depth we use the formula :
\[{\text{refractive index(}}\mu {\text{) = }}\dfrac{{{\text{Real depth}}\left( H \right)}}{{{\text{Apparent depth}}\left( h \right)}}\]
We have given that:-
Real depth (OQ) = 3 cm and refractive index(μ) = 1.5
Now substituting the given value in the above expression. we get:
\[
{\text{1}}{\text{.5 = }}\dfrac{{3{\text{ cm}}}}{{{\text{Apparent depth}}\left( {{\text{OQ'}}} \right)}} \\
\Rightarrow {\text{Apparent depth}}\left( {{\text{OQ'}}} \right){\text{ = }}\dfrac{{{\text{3 cm}}}}{{{\text{1}}{\text{.5}}}} \\
\Rightarrow {\text{Apparent depth}}\left( {{\text{OQ'}}} \right){\text{ = 2 cm}} \\
\]
The image of point Q is formed at Q’. So, the observer at point P will see the apparent image at Q’.
Therefore, the required distance from point P is PQ’= PO + OQ’.
Hence, Option (B) is the correct answer.
Note: The formula used for solving this question came from one of the great applications of Snell’s law of refraction for the case of water and air media systems. It is one of the special cases of refraction when an object is placed in a material medium and the observer sees its image from the air medium. So for solving every system of a pair of media the same formula will not be valid. To tackle such kinds of conceptual questions one should have to derive the various formula for refraction phenomenon and also care about the condition for deriving them like:- the angle of incidence and the refraction is very small such that:- \[\tan \theta \approx \theta ,\sin \theta \approx \theta {\text{ and cos}}\theta \approx {\text{1 for very small }}\theta .\]
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
Change the following sentences into negative and interrogative class 10 english CBSE
Summary of the poem Where the Mind is Without Fear class 8 english CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Write an application to the principal requesting five class 10 english CBSE
What organs are located on the left side of your body class 11 biology CBSE
What is the z value for a 90 95 and 99 percent confidence class 11 maths CBSE