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Angle of prism (mu = 1.5) is 30degree when monochromatic light is incident perpendicular to surface at what angle will it deviate? a) 18degree 36minute b) 22degree 38minute c) 18degree d) 22degree 1minute

Angle of prism (mu = 1.5) is 30degree when monochromatic light is incident perpendicular to surface at what angle will it deviate?  
a) 18degree 36minute 
b) 22degree 38minute
c) 18degree
d) 22degree 1minute
 
 

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Grade:12

2 Answers

Arun
25750 Points
4 years ago
Dear student
 
We know that
n = sin i /sinr 
 
1.5 = sin i / sin 30°
 
sin i = 0.75
 
On solving i = 18°36'
 
Hence Option A is correct.
Vikas TU
14149 Points
4 years ago
Dear student 
The above explanation is very much incorrect , I feel sorry for that, 
You can use the formula \frac{n(prism)}{n(air)}
This is given by {Sin(A+dm)/2} /  Sin(A/2) = \frac{n(prism)}{n(air)}
Put all the values in it A = 30 , and dm is deviation here, 
So , the angle of deviation will comw out to be 15 degree and 16 minute , The ans given in the option is not matching , 
Ans is matching when tou will take (A+dm)/2 , it is 22 degree 83 minute. 
Hope this helps 
Good Luck 

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