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 24 of 34
- A. The distance between wave fronts remains unchanged but the direction of wave front changes
- B. The distance between wave fronts and the direction of wave front both remain unchanged
- C. The distance between wave fronts and the direction of wave front both changes
- D. The distance between wave fronts changes but the direction of wave front remains unchanged
Explanation: The distance between wave fronts and the direction of wave front both changes because wavelength and direction of propagation changes.
Correct answer: The distance between wave fronts and the direction of wave front both changes- A. 4 : 7
- B. 3 : 1
- C. 5 : 3
- D. 6 : 2
Explanation: When two waves with intensity ratio of 4:1 interfere, they create a ratio of maximum to minimum intensities of 3:1.
Correct answer: 3 : 1- A. 1.5 mm
- B. 3 mm
- C. 4.5 mm
- D. 6 mm
Explanation: In a Young's double slit experiment with two different wavelengths, the interference pattern is determined by the path length difference…
Correct answer: 4.5 mm- A. Always bright
- B. Always dark
- C. Either dark or bright depending on the position of S
- D. Neither dark nor bright.
Explanation: When the slits are not equidistant, the central fringe at O can vary in brightness.
Correct answer: Either dark or bright depending on the position of S- A. Zero
- B. Half
- C. One
- D. Two
Explanation: The area of a half period zone is approximately proportional to nm, where m is equal to one.
Correct answer: One- A. Zero
- B. 3 x 10^5 Km sec-1
- C. 3 x 10^8 Km sec-1
- D. Infinite
Explanation: The velocity of light in a vacuum is 3 × 105 Km/sec. This is a constant speed at which light travels in a vacuum.
Correct answer: 3 x 10^5 Km sec-1- A. Vibrations take place in all directions
- B. Vibrations take place in two perpendicular directions
- C. No vibrations at all
- D. Vibrations take place in one plane perpendicular to the directions of propagation of light
Explanation: In plane polarized light, the vibrations of the electromagnetic waves occur in a single plane perpendicular to the direction of light…
Correct answer: Vibrations take place in one plane perpendicular to the directions of propagation of light- A. λ D/d
- B. λd/D
- C. d/λD
- D. Dd/λ
Explanation: In Young's double slit experiment, the fringe spacing is given by the formula λD/d.
Correct answer: λ D/d- A. Coloured fringes will be obtained
- B. Alternate dark and bright light will be seen
- C. No interference fringes will be seen
- D. None of these
Explanation: In Young's double slit experiment using white light, when light passes through the two slits, it undergoes interference, resulting in…
Correct answer: Alternate dark and bright light will be seen- A. Dispersion
- B. Refraction
- C. Reflection
- D. Interference
Explanation: The colors seen in thin soap or oil films result from the interference of light waves.
Correct answer: Interference- A. 16 minutes
- B. 10 minutes
- C. 8 minutes - 30 sec
- D. 8 sec
Explanation: This is very close to the correct time.In reality, light from the Sun reaches Earth in a little over 8 minutes (about 8 minutes 20…
Correct answer: 8 minutes - 30 sec- A. Newton's rings
- B. Rectilinear property of light
- C. Dispersion of white light
- D. Polarisation
Explanation: Newton propounded his corpuscular theory based on the rectilinear property of light, which he believed traveled in straight lines.
Correct answer: Rectilinear property of light- A. Energy only
- B. Momentum only
- C. Both momentum and energy
- D. Momentum end disturbance
Explanation: Electromagnetic waves transport both momentum and energy. The correct option is C.
Correct answer: Both momentum and energy- A. Hertz
- B. Young
- C. Huygen
- D. Maxwell
Explanation: The electromagnetic wave theory was proposed by James Clerk Maxwell. He formulated a set of equations known as Maxwell's equations that…
Correct answer: Maxwell- A. Newton
- B. Fresnel
- C. Maxwell
- D. Huygen
Explanation: The correct answer is Huygen. Christiaan Huygens was a Dutch scientist who proposed the wave theory of light in the 17th century.
Correct answer: Huygen- A. High frequency electromagnetic wave
- B. Low frequency electromagnetic wave
- C. Moderate wavelength electromagnetic wave
- D. Long wavelength electromagnetic wave
Explanation: In 1873, Maxwell's research confirmed that light is a high frequency electromagnetic wave.
Correct answer: High frequency electromagnetic wave- A. Wave nature
- B. Particle nature
- C. Dual nature
- D. None of these
Explanation: The correct answer is Option B: Particle nature. The photo-electric effect involves the ejection of electrons from a material when exposed…
Correct answer: Particle nature- A. Waves
- B. Particles
- C. Photons
- D. Radiations
Explanation: Einstein proposed that light travels in the form of photons, which are packets of energy that exhibit both wave-like and particle-like…
Correct answer: Photons- A. The intensity of light
- B. The frequency of light
- C. Both intensity and frequency
- D. amplitude of the above
Explanation: In the photo-electric effect, the energy of ejected electrons depends on the frequency of light.
Correct answer: The frequency of light- A. Reflection
- B. Refraction
- C. Diffraction
- D. Polarisation
Explanation: Longitudinal waves are characterized by particles vibrating parallel to the direction of wave propagation.
Correct answer: Polarisation