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.
Last updated
665 questions · page 8 of 34
- A. The focal length of the objective lens is increased, and the eye lens is decreased:
- B. Focal lengths of both objective and eyepiece are increased:
- C. The focal length of the eye lens is increased, and that of the objective lens is decreased
- D. Focal lengths of both objective and eyepiece are decreased:
Explanation: Explanation: The magnifying power (M) of a compound microscope is given by M = (1 + D/f) × (1 + D/fe), where D is the least distance of…
Correct answer: The focal length of the eye lens is increased, and that of the objective lens is decreased- A. 2 x 10^8 m/s:
- B. 3 x 10^8 m/s:
- C. 0.5 x 10^8 m/s
- D. (1.5 x 10^8 m/s:
Explanation: Explanation: The speed of light in a medium is given by v = c/n, where c is the speed of light in a vacuum (approximately 3 x 10^8 m/s)…
Correct answer: 0.5 x 10^8 m/s- A. Increases with an increase in age:
- B. Decreases with an increase in age
- C. Neither increases nor decreases:
- D. Becomes infinite after 60 years:
Explanation: Explanation: The least distance of distinct vision (D) decreases with an increase in age.
Correct answer: Decreases with an increase in age- A. (a) Chromatic aberration:
- B. Spherical aberration
- C. Both spherical and chromatic:
- D. Distortion:
Explanation: Explanation: Spherical aberration occurs when parallel rays of light incident on a lens do not converge to a single point due to the…
Correct answer: Spherical aberration- A. Zero:
- B. f:
- C. 2f
- D. f/2:
Explanation: Explanation: When two convex lenses are in contact, their focal lengths add up. Therefore, the resultant focal length is 2f.
Correct answer: 2f- A. (f2 + f1:
- B. f2 - f1
- C. (f1*f1)/(f1 + f2):
- D. (-f1*f2)/(f1 - f2):
Explanation: Explanation: When a convex lens and a concave lens are in contact, their focal lengths subtract.
Correct answer: f2 - f1- A. Real and inverted:
- B. Real and erect:
- C. Virtual and erect
- D. Virtual and inverted:
Explanation: Explanation: The final image produced by a compound microscope is virtual and erect. The eyepiece produces a virtual image.
Correct answer: Virtual and erect- A. f₀ + fₑ
- B. f₀ - fₑ:
- C. f₀/ fₑ:
- D. fₑ/f₀:
Explanation: Explanation: For normal adjustment of an astronomical telescope, the final image is formed at infinity.
Correct answer: f₀ + fₑ- A. 2 Hz:
- B. 5 Hz:
- C. 10 Hz
- D. 0.5 Hz:
Explanation: Explanation: The frequency (f) is given by the formula f=λv , where v is the speed of the wave and λ is the wavelength.
Correct answer: 0.5 Hz:- A. Single mode step index fibre
- B. Multimode step index fibre:
- C. Multimode graded index fibre:
- D. Monomode step index fibre:
Explanation: Explanation: Dispersion causes spreading of different colors of light, leading to signal distortion.
Correct answer: Single mode step index fibre- A. Continuous refraction:
- B. Total internal reflection:
- C. Both continuous refraction and total internal reflection
- D. Diffraction:
Explanation: Explanation: Multimode graded index fibers use both continuous refraction and total internal reflection to guide light signals.
Correct answer: Both continuous refraction and total internal reflection- A. Monomode step index fibre:
- B. Multimode step index fibre:
- C. Multimode graded index fibre:
- D. Single mode step index fibre
Explanation: Explanation: Single mode step index fiber is more suitable for transmission of signals in which white light is used because it allows only…
Correct answer: Single mode step index fibre- A. 0
- B. 45:
- C. -90:
- D. 180:
Explanation: Explanation: The critical angle is the angle of incidence in the denser medium for which the angle of refraction in the rarer medium is 90…
Correct answer: 0- A. Multi-mode step index fibre:
- B. Multi-mode graded index fibre:
- C. Single-mode step index fibre
- D. All types of fibre:
Explanation: Explanation: In a single-mode step index fibre, the core has a uniform refractive index, and the boundary between the core and cladding is…
Correct answer: Single-mode step index fibre- A. Zero (0):
- B. One (1):
- C. Both zero (0) and one (1)
- D. Either zero (0) or one (1):
Explanation: Explanation: In optical communication, a light pulse can represent both binary states: zero (0) and one (1).
Correct answer: Both zero (0) and one (1)- A. Concave lens:
- B. Convex lens
- C. Piano convex lens:
- D. Piano concave lens:
Explanation: Explanation: A lens that is thicker at the center and thinner at the edges is called a convex lens.Just to clarify:Convex Lens: A convex…
Correct answer: Convex lens- A. Wavelength of light
- B. Refractive index of the prism
- C. Wavelength of different colors
- D. All of the above
Explanation: A spectrometer can be used to measure the wavelength of light, the refractive index of a prism, and the wavelengths of different colours -…
Correct answer: All of the above- A. f
- B. f/2
- C. 2f
- D. 3f/2
Explanation: When a convex lens is cut into two identical halves along the lens diameter, each half acts as a separate lens with half the focal length…
Correct answer: f/2- A. Zero
- B. f/2
- C. 2f
- D. Infinite
Explanation: When a convex and concave lens of equal focal lengths are in contact, the combined lens has a focal length equal to half of the individual…
Correct answer: f/2- A. Increases
- B. Decreases
- C. Remains the same
- D. Becomes half
Explanation: The resolving power of a microscope is given by the formula R=λ/2NA , where λ is the wavelength of light and NA is the numerical aperture.
Correct answer: Increases