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 33 of 34
- A. Velocity
- B. Wavelength
- C. Frequency
- D. Amplitude
Explanation: The frequency of light does not change when light travels from one medium to another.
Correct answer: Frequency- A. n=c/v
- B. n=v/c
- C. n=vc
- D. n=v.c
Explanation: This formula represents the index of refraction (n) of a medium, where c is the speed of light in a vacuum, and v is the speed of light in…
Correct answer: n=c/v- A. White
- B. Black
- C. Red
- D. Green
Explanation: Black: The central spot appears black when destructive interference occurs, causing the incident and reflected waves to cancel each other…
Correct answer: Black- A. An electromagnetic wave
- B. A stationary wave
- C. Transverse wave
- D. A longitudinal wave
Explanation: Transverse waves which include all electromagnetic waves such as light, radio waves, and x-rays can be polarized, hence the answer will be…
Correct answer: Transverse wave- A. αmin≥1.22λ/D
- B. αm.λ/D
- C. αmin 2.1 λ/D
- D. αmin ≤1.22λ/D
Explanation: αmin ≥ 1.22λ/D. This is the correct expression for resolving power, known as Rayleigh's criterion, which states that the minimum…
Correct answer: αmin≥1.22λ/D- A. Longer wavelength light
- B. Shorter wavelength light
- C. Wavelength has no effect
- D. It depends only on the design of the microscope not on light
Explanation: Shorter wavelength light improves resolution and provides clearer visibility through a microscope due to its ability to distinguish…
Correct answer: Shorter wavelength light- A. Total internal reflection
- B. Continuous refraction
- C. Both A and B
- D. None of these
Explanation: The total confinement of light for propagation in the optical fiber is obtained through a combination of total internal reflection and…
Correct answer: Both A and B- A. Yellow has less speed
- B. Red light refracts less due to its long wavelength
- C. Actors
- D. Beggars
Explanation: Red light has a longer wavelength compared to yellow light. Longer wavelengths tend to refract less when passing through mediums like the…
Correct answer: Red light refracts less due to its long wavelength- A. Grating plate
- B. Prism
- C. Polaroid
- D. Michelson interferometer
Explanation: The Michelson interferometer is specifically designed for precise measurements of wavelength.
Correct answer: Michelson interferometer- A. Vertical plates
- B. Electron gun
- C. Horizontal plates
- D. Fluorescent screen
Explanation: The time base circuit in a CRO is connected to the horizontal plates. These plates control the horizontal deflection of the electron beam…
Correct answer: Horizontal plates- A. Spectrometer
- B. Telescope
- C. Microscope
- D. Interferometer
Explanation: A spectrometer is an instrument used to measure the properties of light over a specific portion of the electromagnetic spectrum.
Correct answer: Spectrometer- A. wavelength of light
- B. speed of light
- C. frequency of light
- D. Both A and B
Explanation: Both the wavelength and speed of light change when light passes from air to glass.
Correct answer: Both A and B- A. 180°
- B. 120°
- C. 90°
- D. 0°
Explanation: When a light wave passes from a rarer medium to a denser medium, there will be a phase change of 180°.
Correct answer: 180°- A. 0.5
- B. 10
- C. 20
- D. 0.05
Explanation: Magnifying power of telescope = focal length of objective/focal length of eyepiece = power of eyepiece/ power of objective Power of…
Correct answer: 20- A. Interference
- B. Polarization
- C. Diffraction
- D. Dispersion
Explanation: The phenomenon of polarization is used to verify the transverse nature of light.
Correct answer: Polarization- A. Current
- B. Light
- C. Sound
- D. Voltage
Explanation: Optical fibers are designed to guide light, which is used for transmitting data over long distances with minimal loss.
Correct answer: Light- A. 250
- B. 500
- C. 1000
- D. 4000
Explanation: To solve this problem, we use the formula for diffraction grating: d sin(θ) = nλ, where d is the grating spacing, θ is the angle of…
Correct answer: 500- A. Polarized
- B. Refracted
- C. Reflected
- D. Diffracted
Explanation: Light waves can be polarised but sound waves cannot.
Correct answer: Polarized- A. Dispersion
- B. Interference of light
- C. Absorption of light
- D. Scattering of light
Explanation: Multiple colors are observed on the oil floating on water due to the phenomenon of interference.
Correct answer: Interference of light- A. Highly coherent
- B. Plane polarized
- C. Intense
- D. Highly directional
Explanation: A laser beam is sharply focused primarily because it is highly directional.
Correct answer: Highly directional