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 31 of 34
601. According to Huygen's principle, light travels in the form ofI. photonsII. corpusclesIII. wavefronts
- A. I only.
- B. III only.
- C. I and II.
- D. II and III.
Explanation: Huygen's principle states that every point on a wavefront is a source of wavelets, which spread forward at the same speed.
Correct answer: III only.- A. changes its direction due to a change in medium.
- B. reflects from a smooth surface
- C. bends around the obstacles
- D. refracts through a prison
Explanation: Diffraction of light is the phenomenon where light waves bend around the edges of an obstacle or spread out after passing through a small…
Correct answer: bends around the obstacles- A. Diffraction
- B. Pair production
- C. Compton's effect
- D. Photoelectric effect
Explanation: The correct answer is Diffraction. This phenomenon showcases the wave nature of light because it involves the bending and spreading of…
Correct answer: Diffraction- A. Concave lens
- B. Convex lens
- C. Convex mirror
- D. Plane mirror
Explanation: The crest acts as convex lens while the trough acts as concave lens. Therefore, the bright spot on the screen is the crest because the…
Correct answer: Convex lens- A. Diffraction
- B. Reflection
- C. Interference
- D. Refraction
Explanation: "Diffraction" is defined as the process by which a beam of light or any other system of waves is spread out as a result of passing through…
Correct answer: Diffraction- A. Light is partially transmitted into the glass block bending towards the normal and partially reflected
- B. Light is partially transmitted into the glass block bending away from the normal and partially reflected
- C. Light is completely transmitted into the glass and did not reflect in to the liquid
- D. Light is completely reflected back into the liquid
Explanation: When light is being incident from a higher refractive medium to a lower refractive one at an angle of incidence greater than the critical…
Correct answer: Light is completely reflected back into the liquid- A. Reflect
- B. Refract
- C. Both
- D. None of these
Explanation: An electron beam can be refracted at the interface between a plasma and a gas, much as light is refracted at an air-water interface.
Correct answer: Both- A. 4
- B. 10
- C. 40
- D. 400
Explanation: The resolving power can be calculated as; 40/10 = 4. Hence, A is correct option.
Correct answer: 4- A. 1
- B. 2
- C. 3
- D. 4
Explanation: The explanation is given below:Wavelength of light, λ = 450 nm = 4.5×10^-5cmNumber of lines per cm, N = 5000Required:The orders of spectra…
Correct answer: 4- A. Above 300 nm
- B. Below 300 nm
- C. In between UV to IR
- D. None of these
Explanation: The spectrum of white light consists of six basic colours arranged in a specific order: red, orange, yellow, green, blue and violet.i.e…
Correct answer: In between UV to IR- A. Transverse waves
- B. Longitudional waves
- C. Mechanical waves
- D. None of these
Explanation: The waves in which all points oscillate at right angles to the mean position are known as transverse waves.
Correct answer: Transverse waves- A. Speed
- B. Frequency
- C. Distance
- D. Amplitude
Explanation: Michelson's interferometer is an instrument that can be used to measure distance.
Correct answer: Distance- A. Interference
- B. Polarization
- C. Diffraction
- D. None of these options are correct
Explanation: The Davisson-Germer experiment is used to explain diffraction. The Davisson-Germer experiment, conducted by Clinton Davisson and Lester…
Correct answer: Diffraction- A. 700 Å - 1000 Å
- B. 1 nm - 100 nm
- C. 0.1n m - 1 nm
- D. 4000 Å - 7000 Å
Explanation: Visible light has a wavelength ranging between 400 nm to 700 nm. 1 nm has 10 Å. Therefore, the range can be written as 4000 Å to 7000 Å.
Correct answer: 4000 Å - 7000 Å- A. Telescope
- B. Turntable
- C. Cross wire of telescope
- D. None of these options are correct
Explanation: The turntable is the major part of the instrument. It is mounted on a robust bearing, and it can be rotated around a vertical axis.
Correct answer: Turntable- A. Reflect
- B. Refract
- C. Both Options A and B are correct
- D. None of these options are correct
Explanation: A beam of electrons can both reflect and refract from surfaces.
Correct answer: Both Options A and B are correct- A. Visible light.
- B. Invisible infra-red.
- C. Ultra-violet.
- D. Ordinary light.
Explanation: In a material the speed of a wave, light, becomes v=c/n, where n is the refractive index of the material, n differs for each wavelength…
Correct answer: Invisible infra-red.- A. 50 to 1000
- B. 50
- C. 30
- D. 5
Explanation: A single mode or monomode step index fibre allows the propagation of only one transverse electromagnetic mode and hence the core diameter…
Correct answer: 5- A. Telescope
- B. Convex mirror
- C. Convex lens
- D. Concave lens
Explanation: Convex lenses are used in eyeglasses as they increase refraction and accordingly reduce the focal length hence making the images look…
Correct answer: Convex lens- A. Image size to object size.
- B. Object size to image size.
- C. Eyepiece size to object size.
- D. None of these.
Explanation: The magnification produced by a lens is defined as the 'ratio of the height of the image or image distance, to the height of the object or…
Correct answer: Image size to object size.