Question

For the angle of minimum deviation, the refracted ray becomes:​

Answer 1

Answer:

Correct option is

B

Lies between 2 and 2

The angle of minimum deviation is given as

δmin=i+e−A

for minimum deviation

δmin=A then

2A=i+e

in case of δmin; i=e

2A=2i r1=r2=2A

i=A=90∘

1sinr=nsinr1

sinA=nsin2A

2sin2Acos2A=nsin2A

2cos2A=n

when A=90∘=imin

then nmin=2

i=A=0 

nmax=2.

Answer 2

Answer:

In minimum deviation, the refracted ray in the prism is parallel to its base. In other words, the light ray is symmetrical about the axis of symmetry of the prism. Also, the angles of refractions are equal i.e. r1 = r2. And, the angle of incidence and angle of emergence equal each other (i = e).