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 20 of 34
- A. Particle nature of electron
- B. Wave nature of electron
- C. Dual nature of electron
- D. None of the above
Explanation: The electron microscope is a powerful scientific instrument that employs a beam of electrons to illuminate an object and magnify its…
Correct answer: Wave nature of electron- A. Brewster's Law
- B. Malu's Law
- C. Bragg's Law
- D. Grimaldi's Law
Explanation: Brewster's law gives a relationship for light waves stating that the maximum polarization (vibration in one plane only) of a ray of light…
Correct answer: Brewster's Law- A. Addition of two coherent waves to produce a stationary wave pattern.
- B. Bending of waves round an obstacle
- C. Change of direction when waves cross the boundary between one medium and another.
- D. Splitting of white light into colours.
Explanation: Diffraction is the spreading of waves around obstacles.
Correct answer: Bending of waves round an obstacle- A. Magnifying power
- B. Angular magnification
- C. Simple magnification
- D. Both Magnifying power and Angular Magnification
Explanation: The ratio of the angle subtended at the eye by an image to the angle subtended at the eye by an object is known as the angular…
Correct answer: Angular magnification- A. Constructive interference
- B. Destructive interference
- C. Stationary interference
- D. Simple interference
Explanation: Destructive interference occurs when waves come together so that they completely cancel each other out and when the path difference…
Correct answer: Destructive interference- A. Reflect less
- B. Diffract less
- C. Reflect more
- D. Diffract more
Explanation: When a light ray passes through a small opening, it undergoes a phenomenon known as diffraction.
Correct answer: Diffract more- A. in curtain-less windows
- B. for calculating the fringe spacing
- C. for finding concentration of sugar in blood
- D. for controlling the head light glares in night driving
Explanation: Polarization of light refers to the alignment of the electric field vectors of light waves in a particular direction.
Correct answer: for calculating the fringe spacing- A. interference
- B. diffraction
- C. polarization
- D. dispersion
Explanation: Therefore, the longer wavelength of sound waves allows them to diffract around corners to a greater extent compared to visible light…
Correct answer: diffraction- A. diffraction
- B. interference
- C. polarization
- D. photoelectric effect
Explanation: Huygens's wave theory of light cannot explain the photoelectric effect (d).
Correct answer: photoelectric effect- A. polarization
- B. interference
- C. diffraction
- D. none
Explanation: When light waves encounter sharp edges or small openings, they bend slightly around them. This phenomenon is called diffraction.
Correct answer: diffraction- A. refraction
- B. reflection
- C. scattering
- D. dispersion
Explanation: As the sun rises or sets, its light travels through a greater thickness of the atmosphere compared to when it's high in the sky.
Correct answer: refraction- A. its wavelength night increases
- B. neither its wavelength nor its frequency changes
- C. its frequency increases
- D. its wavelength decreases
Explanation: When a ray of light enters a denser medium like glass from a less dense medium like air, the following happens:Speed of light decreases…
Correct answer: its wavelength decreases- A. Remain same
- B. Reduce to one half
- C. Reduce to one quarter
- D. Increase to twice
Explanation: y=λD/d, where y is the spacing between two adjacent bright fringes Where d is the spacing between the slit and D is the linear distance…
Correct answer: Reduce to one quarter- A. More frequency, less wavelength
- B. Less frequency, less wavelenght
- C. Less frequency, more wavelenght
- D. More frequency, more wavelength
Explanation: A fact that red light has a greater wavelength while wavelength and frequency are inversely proportional to each other hence, red light…
Correct answer: Less frequency, more wavelenght- A. Virtual
- B. Erect
- C. Real
- D. Both Virtual and Erect
- E. Both Erect and Real
Explanation: The object is placed 10 cm from a converging lens with a focal length of 20 cm, meaning it is inside the focal point.
Correct answer: Both Virtual and Erect- A. True
- B. False
- C. Uncertain
- D. None of these
Explanation: The statements tell us that Josh > Stephen and Darren > Stephen. However, there is no information to directly compare the number of movies…
Correct answer: Uncertain- A. 115 mm
- B. 235 mm
- C. 417 mm
- D. 716 mm
- E. 617 mm
Explanation: The correct answer is 235 mm. To find the distance between the lenses, use the formula: 1/f = 1/v - 1/u for the objective lens, where f is…
Correct answer: 235 mm- A. 10 cm
- B. 20 cm
- C. 30 cm
- D. 40 cm
Explanation: This is the correct answer. To form an erect image twice as large as the object using a convex lens, the object must be placed between the…
Correct answer: 10 cm- A. Coulomb's Law
- B. Bragg's Law
- C. Faraday's Law
- D. Ohm's Law
- E. Gravitational Law
Explanation: Coulomb's Law: the force of attraction or repulsion between two charged bodies is directly proportional to the product of their charges…
Correct answer: Bragg's Law- A. 1.48
- B. 1.58
- C. 1.62
- D. 1.72
Explanation: To achieve dispersion without deviation when combining two prisms, the product of the refractive index and the angle of the prism must be…
Correct answer: 1.72