18 aÎźg=
1/gÎźa
Sin i / sin r = sin e / sin r Sin i = sin e i = e Inclinations of incident ray and emergent ray are same. The two rays are parallel. Also total deviation of slab = deviation at first boundary + deviation at second boundary d = d1+d2 = ( i - r) + ( r - e ) = i - e but i = e d = 0 The incident and emergent rays are parallel. iii) The incident ray PO1 and emergent ray QO2 are parallel but displaced laterally through a distance called lateral shift (S).
Lateral shift S = perpendicular distance between PO 1 and QO2 A ray of light on passing through the rectangular slab has only undergone lateral shift without deviation. Replace the slab on the marked boundaries, let the pins be in place L1, L2 on PO1 and L3, L4 on QO2. Now look through the face1 and observe images of L 3 and L4. The images of L3,L4 are collinear with L1and L2. Agastya International Foundation. For Internal Circulation only. Request to Readers- Kindly mail details of any discrepancies or mistakes to handbooks.agastya@gmail.com