Wave Optics NEET MCQs

Start With Wave Optics Formulae

Revise these high-yield formulae first, then attempt the MCQs below.

• Wave speed: v = f lambda.
• Phase difference: Delta phi = 2 pi Delta x / lambda.
• Young double slit path difference: Delta x = d sin theta approximately dy / D.
• Fringe width in YDSE: beta = lambda D / d.
• Bright fringes: y_n = n lambda D / d.
• Dark fringes: y_n = (2n - 1) lambda D / 2d.
• Interference intensity: I = I1 + I2 + 2 sqrt(I1 I2) cos phi.
• Maximum and minimum intensities: I_max = (sqrt I1 + sqrt I2)^2, I_min = (sqrt I1 - sqrt I2)^2.
• Thin film optical path difference at normal incidence: 2 mu t.
• Single slit diffraction minima: a sin theta = n lambda.
• Angular width of central diffraction maximum: 2 lambda / a.
• Resolving power of telescope: proportional to aperture / lambda; angular limit = 1.22 lambda / D.
• Microscope resolving limit: d_min = lambda / (2 NA), so resolving power increases when wavelength decreases.
• Malus law: I = I0 cos^2 theta.
• Unpolarised light through one ideal polaroid: I = I0 / 2.
• Brewster law: tan i_p = mu, and reflected and refracted rays are perpendicular at i_p.
• Doppler shift for light at low speed: Delta lambda / lambda approximately v / c.
• Red shift means wavelength increases; the source is receding.