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CG PET Ray and Wave Optics — practice questions

Explore 60 free Ray and Wave Optics questions in CG PET Physics. Open each question or exercise to read its content, reference answers and available explanation.

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Ray and Wave Optics questions and exercises with answers

Showing questions 1–30 of 60.

Snell's law of refraction states:Read the answer and worked solution →For a plane mirror, image is:Read the answer and worked solution →Focal length of a concave mirror with radius of curvature R:Read the answer and worked solution →For a thin lens, lens-maker's formula:Read the answer and worked solution →Refraction by a prism: deviation δ depends on:Read the answer and worked solution →Snell's law states:Read the answer and worked solution →Apparent depth of object at real depth d in water (n = 4/3) seen from above is:Read the answer and worked solution →Refractive index of medium where speed of light is v is:Read the answer and worked solution →For a concave mirror, focal length f relates to radius of curvature R as:Read the answer and worked solution →Object placed beyond center of curvature C of a concave mirror gives image that is:Read the answer and worked solution →For a convex lens, object placed at 2f forms image at:Read the answer and worked solution →Power of a lens of focal length 20 cm (in dioptres):Read the answer and worked solution →Two thin lenses with powers +5 D and -3 D in contact. Equivalent power:Read the answer and worked solution →For thin prism of refracting angle A (small), deviation δ is approximately:Read the answer and worked solution →Critical angle for glass-air interface (n_glass = 1.5):Read the answer and worked solution →In optical fibers, light travels by:Read the answer and worked solution →In Young's double slit experiment, fringe width β with screen at distance D and slit separation d:Read the answer and worked solution →For YDSE with λ = 500 nm, d = 0.2 mm, D = 1 m, fringe width is:Read the answer and worked solution →Resolving power of telescope with aperture D and wavelength λ (Rayleigh criterion):Read the answer and worked solution →Brewster's law: at angle of polarization i_B, the relation between i_B and refractive index n is:Read the answer and worked solution →Resolving power of microscope is proportional to:Read the answer and worked solution →Two coherent sources of intensities I₁ and I₂ interfere. Maximum intensity in pattern:Read the answer and worked solution →For thin-film interference (oil on water), constructive interference for reflection condition:Read the answer and worked solution →Refractive index of medium 1 with respect to medium 2 (denoted ₁n₂ or n₁/n₂). If ₁n₂ = 1.5 and ₂n₃ = 4/3, then ₁n₃ =Read the answer and worked solution →Speed of light in glass (n = 1.5) is approximately:Read the answer and worked solution →Diffraction effects are more noticeable when the obstacle/aperture size is:Read the answer and worked solution →For thin lens, when image distance equals object distance (|v| = |u|), object position is:Read the answer and worked solution →Pick the higher optical valueRead the answer and worked solution →Sort microscope from telescopeRead the answer and worked solution →Key in the ray optics answersRead the answer and worked solution →

Worked practice questions

Snell's law of refraction states:

  1. n₁/sin θ = n₂
  2. n₁ sin θ₁ = n₂ sin θ₂
  3. sin θ₁ = sin θ₂
  4. n₁ cos θ₁ = n₂ cos θ₂
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Correct answer: B. n₁ sin θ₁ = n₂ sin θ₂

**Snell's law:** n₁ sin θ₁ = n₂ sin θ₂, where θ₁, θ₂ are angles measured from normal. n = c/v (refractive index). When light enters denser medium, it bends toward normal.

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For a plane mirror, image is:

  1. Virtual, inverted
  2. Real, magnified
  3. Real, inverted
  4. Virtual, erect, same size, behind mirror
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Correct answer: D. Virtual, erect, same size, behind mirror

Plane mirror produces virtual (cannot be projected on screen), erect, same-size image as far behind the mirror as object is in front. Lateral inversion (left ↔ right).

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Focal length of a concave mirror with radius of curvature R:

  1. -R
  2. 2R
  3. R/2
  4. R
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Correct answer: C. R/2

f = R/2 for spherical mirrors (paraxial approximation). For concave (converging) mirror, f > 0 by convention for convex (diverging), f < 0.

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