Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

JEE Class main Answered

Please solve the question in the attached file.
question image
Asked by hemeshsaini2005 | 26 Oct, 2021, 13:49: PM
answered-by-expert Expert Answer
If the light ray retraces its path after reflection means , mirror is oriented normal to the emergent ray from prism.
 
Incident light ray is horizontal . if angle of prism is A , then angle of incidence of light ray is A/2
 
angle of refraction r1 at the incident surface of prism is determined by law of refraction
 
sin(A/2)  / sin(r1)  = 1.5      or  sin(r1 )  = sin(2) / 1.5 = 0.023    , hence r1 = 1.33o
 
Let r2 be the angle of incidence at emergent surface of prism .
 
In a prism , we have ,  A  = r1 + r2   , hence  we get  r2 = A - r1 = 4 - 1.33 = 2.67o
 
Angle of emergence e is determined by law of refraction
 
sin ( e ) / sin (r2 ) = 1.5   , sin (e ) = 1.5  sin 2.67 = 4o   
 
Now let us position the mirror normal to emergent ray . Then light ray retraces its path
Let us extend the normal to the light emerging surface of prism to mirror as shown in figure as the line QT.
Let the light ray incident on mirror at R . From R , let us draw line RS that is parallel to light emerging surface of prism.
 
Since begin mathsize 14px style angle end styleQRT  = begin mathsize 14px style angle end styleQSR = 90o ,  begin mathsize 14px style angle end styleSQR = begin mathsize 14px style angle end styleSRT = e .
From figure it is seen that mirror is to be rotated by ( begin mathsize 14px style angle end styleSRT - (A/2 ) ) =  ( 4 - 2 ) = 2o
    
Answered by Thiyagarajan K | 27 Oct, 2021, 21:11: PM
Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
JEE main - Physics
what is u-v rule
Asked by kunalauditore94 | 21 Aug, 2024, 19:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
point object is placed at a distance d from a convex lens of focal length 10 cm. If a plane mirror were put perpendicular to principal axis of lens at distance of 25cm form it , what are the values of d so that the image forms at the point object
Asked by pranav10022007 | 12 May, 2024, 10:05: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
A double convex lens has two surface of equal radii R and refractive index 1.5 ,then focal length f
Asked by sreelekhachakali2006 | 15 Mar, 2024, 10:35: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
a prism of refractive index 1.5 produces minimum deviation 40. find the angle of prism
Asked by ramanjaneyuluoguru | 22 Jan, 2024, 12:30: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
a concave lens is dipped in a liquid whose, refractive index is equal to refractive index of the lens then it's focal length of lens is
Asked by kumarpurshotam451 | 29 Sep, 2023, 15:46: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
the apprent depth of water in cylinderical water tank of diameter 2R is reducing at the rate of x cm/min when is being drained out at a constant rate . the amount of water drained in cc/min is
Asked by kumarpurshotam451 | 27 Sep, 2023, 16:57: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Question is in the image attached
question image
Asked by swayamagarwal2114 | 15 Jul, 2022, 09:19: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Question is in the image attached
question image
Asked by swayamagarwal2114 | 15 Jul, 2022, 09:18: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
why laser light is difficult to obtain at infrared wavelengths as compared to ultraviolet wavelengths?
Asked by 3047-manvir | 05 Jul, 2022, 12:09: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
plz solve this numerical ***************************** A coherent length of sodium D2 line is 2.5 cm .deduce coherence time , spectral width of line, and purity factor .given wavelength=5990A°
Asked by 3047-manvir | 04 Jul, 2022, 12:33: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt