Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

For an isosceles prism of angle A and refractive index μ , it is found that the angle of minimum deviation  δm=A. Which of the following options is/are correct?

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.
An Intiative by Sri Chaitanya

a

For the angle of incidence i1=A, the ray inside the prism is parallel to the base of the prism

b

At minimum deviation, the incident angle i1 and the refracting angle r1 at the first refracting surface are related by  r1=i1/2

c

For this prism, the emergent ray at the second surface will be tangential to the surface when the angle of incidence at the first surface isi1=sin−1sinA4cos2A2−1−cosA

d

For this prism the refractive index μ and the angle of prism A are related as A=12cos−1μ2

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

δm=A & μ=sin⁡A+δ¯m2sin⁡A/2⇒μ=sin⁡Asin⁡A/2⇒μ=2sin⁡A/2cos⁡A/2sin⁡A/2=2cos⁡A/2⇒cos⁡A/2=(μ/2)⇒(A/2)=cos−1⁡(μ/2)⇒A=2cos−1⁡(μ/2) (D) is not correct. δm=i1+i2−A⇒i1+i2=2A and i1=i2=ASo option A is correct.r1=r2 and μ=sin⁡i1sin⁡r12cos⁡A/2=sin⁡Asin⁡r1⇒sin⁡r1=2sin⁡A/2cos⁡A/22cos⁡A/2⇒r1=A/2=i1/2 option (B) is correct Emergent ray tangential to the surface meansi2=90∘⇒r2=C (critical angle) r1=(A−C)μ=sin⁡i1sin⁡r1sin⁡i1=μsin⁡r1=2cos⁡A/2[sin⁡(A−C)]=2cos⁡A/2(sin⁡Acos⁡C−cos⁡Asin⁡C)=2cos⁡A/2sin⁡A1−sin2⁡C−cos⁡A1μ=2cos⁡A/2sin⁡A1−1μ2−cos⁡A1μ=2cos⁡A/2sin⁡A1−14cos2⁡A/2−cos⁡A12cos⁡A/2=2cos⁡A/2sin⁡A4cos2⁡A/2−12cos⁡A/2−cos⁡A12cos⁡A/2=sin⁡A4cos2⁡A/2−1−cos⁡A⇒i1=sin−1⁡sin−1⁡A4cos2⁡A/2−1−cos⁡AOption C is correct
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon