Practice question

**Refraction through prism** deviation δ = i+e-A, minimum when i=e, symmetrical path, r₁=r₂=A/2, n = sin[(A+δ_m)/2]/sin(A/2). In water n_rel = n_prism/n_water =1.5/1.33=1.128, so δ_m reduces because relative index lower, new δ_m from formula with n_rel. Focal length: f = 16 cm (convex mirror). Image distance: v = 8 cm (virtual image). Mirror equation: (1/v) + (1/u) = (1/f) . (1/8) + (1/u) = (1/16) ⇒ (1/u) = (1/16) - (1/8) = (1 - 2/16) = (-1/16) . u = -16 cm . Substituting values gives 12 cm, which matches expected image position and magnification from mirror/lens formula 1/f = 1/v - 1/u (lens) or 1/f