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Essential formulas for JEE Ray Optics: Mirror: 1/v + 1/u = 1/f, m = -v/u. Lens: 1/v - 1/u = 1/f, m = v/u. Lens maker: 1/f = (n_{2}/n_{1} - 1)(1/$R_{1}$ - 1/$R_{2}$). Combination: P = $P_{1}$ + $P_{2}$ (contact), P = $P_{1}$ + $P_{2}$ - dP_{1}$$P_{2} (separated). Prism: δ = i_{1} + i_{2} - A, n = sin((A+δ_m)/2)/sin(A/2), thin prism δ = (n-1)A. TIR: sinθ_c = n_{2}/n_{1}. Microscope: M = (L/f_o)(1+D/f_e). Telescope: M = f_o/f_e. Silvered lens: P_eq = 2P_lens + P_mirror.

JEE strategy: (1) Always apply sign convention consistently before substituting. (2) For prism problems, check if it's a thin prism first — simplifies calculations significantly. (3) In lens combination problems, work sequentially through each lens. (4) For moving object problems, differentiate the mirror/lens formula. (5) Remember that mirror properties are independent of the medium. (6) In instrument problems, identify whether the image is at near point or infinity before choosing the magnification formula. Ray optics carries approximately 5% weightage with 1-2 MCQs and occasional numerical.