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 26 of 34
501. In Young's double slit experiment, the distance between two consecutive bright or dark fringes is:
- A. dλ / L
- B. Lλ / d
- C. d / Lλ
- D. L / λd
Explanation: The formula Lλ / d is the correct one to use in Young's double slit experiment for finding the distance between consecutive bright or dark…
Correct answer: Lλ / d- A. (m+1/2) L λ / d, where m=0,1,2,3,...
- B. (m-1/2) L λ / d, where m=0,1,2,3,...
- C. m(L λ / d), where m=0,1,2,3,...
- D. (m+1/2) d / L λ , where m=0,1,2,3,...
Explanation: The correct formula to find the position of the m-th bright fringe in Young's double slit experiment is m(L λ / d), where m=0,1,2,3,...
Correct answer: m(L λ / d), where m=0,1,2,3,...- A. Coloured fringes will be observed
- B. Bright fringes will be observed
- C. Alternate dark and bright fringe will be observed
- D. No interference fringes will be seen
Explanation: Young's double slit experiment requires monochromatic light to observe interference fringes.
Correct answer: No interference fringes will be seen- A. d sin θ = m λ if m=0,1,2,3,....
- B. d sin θ = (m+1/2) λ if m=0,1,2,3,...
- C. d sin θ = (m-1/2) λ if m=0,1,2,3,...
- D. d sin θ = m/ λ
Explanation: In Young's double slit experiment, the condition for destructive interference is when the path length difference between the two waves is…
Correct answer: d sin θ = (m+1/2) λ if m=0,1,2,3,...- A. Wavelength of monochromatic light
- B. Distance between the slits
- C. Fringe spacing
- D. All of these
Explanation: Young's double slit experiment is a fundamental demonstration in optics that allows for the determination of multiple properties of light.
Correct answer: All of these- A. To control head light glare in night driving
- B. To determine the concentration of optically active substance
- C. In curtain less window to adjust the amount of light
- D. All of them
Explanation: Polaroids can be used in various scenarios, including controlling headlight glare in night driving, determining the concentration of…
Correct answer: All of them- A. d sin θ = m λ
- B. d sin θ = m λ /2
- C. d sin θ = 2m λ
- D. d sin θ = m+ λ /2
Explanation: The correct relation for Bragg's law is given by d sin θ = m λ /2. This formula represents the relationship between the spacing of crystal…
Correct answer: d sin θ = m λ /2- A. Blue
- B. Red
- C. Black
- D. Purple
Explanation: When monochromatic red light is shone on a blue book, the book will appear black.
Correct answer: Black- A. Interference
- B. Diffraction
- C. Polarization
- D. Reflection
Explanation: Polarization is the property that sets light waves apart from sound waves.
Correct answer: Polarization- A. Bragg's law
- B. Diffraction grating
- C. Compton effect
- D. Photo electric effect
Explanation: Diffraction gratings are not suitable for measuring the wavelength of X-rays due to their much shorter wavelengths compared to visible…
Correct answer: Diffraction grating- A. Young's double slit experiment
- B. Diffraction grating
- C. Bragg's law
- D. Photoelectric effect
Explanation: Bragg's law is specifically designed to measure the wavelength of X-rays by utilizing crystal structures to create interference patterns.
Correct answer: Bragg's law- A. λ
- B. λ/ 2
- C. λ/ 4
- D. 2λ
Explanation: In Michelson's interferometer, in order to observe two successive bright or dark fringes, the movable mirror needs to be displaced through…
Correct answer: λ/ 2- A. 5000 Ao
- B. 500 Ao
- C. 50 Ao
- D. 5 Ao
Explanation: To calculate the wavelength of light, we use the formula: wavelength = (mirror displacement / fringe count) * 2.
Correct answer: 5000 Ao- A. 1
- B. 2
- C. 3
- D. 4
Explanation: When the movable mirror in Michelson's interferometer is displaced by a distance equal to the wavelength of monochromatic light, a path…
Correct answer: 2- A. Wavelength of light
- B. Velocity of light
- C. Amplitude of light
- D. Dispersion of light
Explanation: Michelson interferometer is primarily used to study the interference of light waves and determine their wavelength.
Correct answer: Wavelength of light- A. Curved lines
- B. Straight lines
- C. Sometimes curved and sometimes in straight line
- D. None of these
Explanation: Light waves never travel in curved lines. If they travel in curved lines , then they would not cast shadows of objects placed in their…
Correct answer: Straight lines- A. Reflection
- B. Rarefraction
- C. Polarization
- D. Interference
Explanation: Reflection is the correct answer because it describes the bouncing back of light when it encounters a boundary between two different…
Correct answer: Reflection- A. Specular refraction
- B. Regular refraction
- C. Irregular refraction
- D. None of these
Explanation: Irregular refraction is the correct answer because it explains the non-uniform change in direction of light passing through a medium with…
Correct answer: Irregular refraction- A. Real
- B. Virtual
- C. Curved
- D. None of these
Explanation: The correct answer is Option B: Virtual. When a real object is placed in front of a plain mirror, the image formed is virtual.
Correct answer: Virtual- A. Real
- B. Virtual
- C. Inverted
- D. Erect
Explanation: A real image is formed when light rays converge at the image location, creating a focused projection that can be displayed on a screen.
Correct answer: Real