Free Optics MCQs with Answers
665 Optics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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665 questions · page 6 of 34
- A. one slit is for frequency, the other for wavelength
- B. wo slits in parallel offer less resistance
- C. to increase the intensity
- D. to create a path length difference
Explanation: In Young's double-slit experiment, the presence of two slits allows for the creation of a path length difference between the light waves…
Correct answer: to create a path length difference- A. diffraction
- B. interference
- C. polarization
- D. photoelectric effect
Explanation: Huygens' wave theory successfully explains phenomena such as diffraction, interference, and polarization.
Correct answer: photoelectric effect- A. 3π/4
- B. π
- C. 2π
- D. π/2
Explanation: In a Young's double-slit experiment, the central bright fringe (zeroth-order fringe) occurs when waves from the two slits have a path…
Correct answer: 2π- A. Use slits that are closer together
- B. Use a light source of lower intensity
- C. Use a blue filter instead of a yellow filter
- D. Use a light source of higher intensity
Explanation: The spacing of interference fringes in a Young's double-slit experiment is determined by the wavelength of light and the distance between…
Correct answer: Use slits that are closer together- A. reflection
- B. Use a light source of lower intensity
- C. diffraction
- D. polarization
Explanation: Longitudinal waves, such as sound waves, do not exhibit polarization. Polarization involves the orientation of oscillations in a…
Correct answer: polarization- A. the angle to the second maximum
- B. the angle to the first minimum
- C. the phase angle between the extreme rays
- D. N⋅π where N is an integer
Explanation: In the equation for single-slit diffraction, sin(θ)=aλ , θ represents the angle to the first minimum (first dark fringe).
Correct answer: the angle to the first minimum- A. the slit width
- B. the number of slits
- C. the order of the line
- D. the slit separation
Explanation: Explanation: In the equation dsinθ=mλ for a diffraction grating, m represents the order of the line.
Correct answer: the order of the line- A. crest
- B. trough
- C. wavelength
- D. wavefront
Explanation: Explanation: The locus of all points in a medium having the same phase of vibration is called a wavefront.
Correct answer: wavefront- A. light from sodium lamp
- B. light from mercury lamp
- C. light from sodium fluorescent tube
- D. light from a simple lamp
Explanation: Explanation: Nearly monochromatic light refers to light that consists of a very narrow range of wavelengths.
Correct answer: light from sodium lamp- A. same wavelength
- B. same amplitude of vibration
- C. same wavelength with constant phase difference
- D. same amplitude and wavelength
Explanation: Explanation: Coherent sources of light emit waves with the same wavelength and a constant phase difference.
Correct answer: same wavelength with constant phase difference111. When the crest of one wave falls over the trough of the other wave, this phenomenon is known as
- A. polarization
- B. constructive interference
- C. destructive interference
- D. diffraction
Explanation: Explanation: Destructive interference occurs when the crest of one wave coincides with the trough of another wave.
Correct answer: destructive interference- A. 1/2
- B. 3/2
- C. 2/3
- D. 2/1
Explanation: Explanation: For a diffraction grating, the condition for intensity maxima is given by dsinθ=mλ, where d is the grating spacing, θ is the…
Correct answer: 2/3- A. integral multiple of λ/2
- B. integral multiple of λ
- C. odd integral multiple of λ/2
- D. even integral multiple of λ
Explanation: Explanation: The condition for constructive interference is that the path difference between two coherent waves should be an integral…
Correct answer: integral multiple of λ- A. bright fringes are wider than dark fringes
- B. dark fringes are wider than bright fringes
- C. both dark and bright fringes are of equal width
- D. central fringes are dimmer than the outer fringes
Explanation: Explanation: In an interference pattern, both dark and bright fringes have the same width.
Correct answer: both dark and bright fringes are of equal width- A. remain the same
- B. double
- C. half
- D. quadrupled
Explanation: In Young's double-slit experiment, if the separation between the slits is halved and the distance between the slits and screen is doubled…
Correct answer: quadrupled- A. diffraction
- B. reflection
- C. polarization
- D. scattering
Explanation: Explanation: The blue color of the sky is primarily due to Rayleigh scattering.
Correct answer: scattering- A. 0
- B. 90
- C. 180
- D. 45
Explanation: Explanation: When light travels from a denser medium to a rarer medium, it undergoes a phase change of 180 degrees upon reflection.
Correct answer: 180- A. 5000 nm
- B. 5000 Angstrom
- C. 500 m
- D. 2000 micrometer
Explanation: Explanation: The number of fringes (N) observed in a Michelson Interferometer is given by the formula N=λ2d , where d is the mirror…
Correct answer: 5000 Angstrom- A. 10 Angstrom
- B. 1000 Angstrom
- C. 1 Angstrom
- D. 100 Angstrom
Explanation: Explanation: X-rays have wavelengths on the order of Angstroms, specifically around 1 Angstrom (10^(-10) meters).
Correct answer: 1 Angstrom- A. 4x10^(-10) m
- B. 1000 Angstro-2x10^(-10) m
- C. 0.02x10^(-10) m
- D. 20x10^(-10) mm
Explanation: Explanation: For the first-order diffraction, the Bragg's law is given by 2dsinθ=mλ, where d is the spacing between atomic planes, θ is…
Correct answer: 0.02x10^(-10) m