Concepts Of Physics MCQ Edition [Volume 1]PhysicsDispersion and Spectra
A thin prism of angle 6.0^ , = 0.07 and _y = 1.50 is combined with another thin prism having = 0.08 and _y = 1.60 . The combination produces no deviation in the mean ray. Determine: (i) the angle of the second prism, (ii) the net angular dispersion produced by the combination when a beam of white light passes through it, (iii) the deviation in the mean ray if the prisms are similarly directed, and (iv) the angular di
Options
- A(i) 5^ , (ii) 0.03^ , (iii) 6^ , (iv) 0.45^
- B(i) 6^ , (ii) 0.04^ , (iii) 7^ , (iv) 0.55^
- C(i) 5^ , (ii) 0.06^ , (iii) 6^ , (iv) 0.40^
- D(i) 4^ , (ii) 0.02^ , (iii) 5^ , (iv) 0.35^
Correct answer
A. (i) 5^ , (ii) 0.03^ , (iii) 6^ , (iv) 0.45^
Step-by-step solution
For the first prism, the deviation of the mean ray is given by ₁ = ( _ y1 - 1)A₁ . Substituting the given values, ₁ = (1.50 - 1) 6.0^ = 3.0^ . For the combination to produce no deviation in the mean ray, the prisms must be oppositely directed and their deviations must be equal in magnitude, so ₂ = ₁ = 3.0^ . The deviation for the second prism is ₂ = ( _ y2 - 1)A₂ . Substituting the values, 3.0^ = (1.60 - 1)A₂ 0.60 A₂ = 3.0^ A₂ = 5.0^ . The angular dispersion produced by a prism is = . For the first prism, ₁ = 0.07