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 18 of 34
- A. Speed
- B. Wavelength
- C. Frequency
- D. All three
Explanation: The frequency of light does not change with the change of medium because it depends on the frequency of the source of light.
Correct answer: Frequency- A. 2D image
- B. None of these
- C. 3D image
- D. SD image
Explanation: A scanning electron microscope (SEM) produces a three-dimensional (3D) image.
Correct answer: 3D image- A. Magnetic in nature
- B. None of these
- C. Electric in nature
- D. Both
Explanation: Polarization of light is the process of transforming unpolarized light to polarized light. Polarized light only vibrates in one plane.
Correct answer: Both- A. Increases
- B. Decreases
- C. Remains same
- D. None of these
Explanation: Increasing the wavelength of the light increases the spacing between different fringes since the spacing between different fringes is…
Correct answer: Increases- A. Incident light
- B. Reflected light
- C. Any of a or b
- D. None of these
Explanation: An incident ray is a rectilinear ray of light that strikes a surface, known as an incident ray on that spot(surface).
Correct answer: Incident light- A. Electric in nature
- B. Magnetic in nature
- C. Both A and B
- D. None of these
Explanation: Light is the interaction of electric and magnetic fields traveling through space.
Correct answer: Both A and B- A. 13
- B. 26
- C. 42.5
- D. 39.5
Explanation: D x sinθ = λ x order sin-1 = 450 x 10^-9 x 3/5000 x 100 = 42.45
Correct answer: 42.5- A. The width of central maximum is decreased
- B. The width of the outer maximum is decreased
- C. The intensity of the central maximum will increase
- D. Less number of fringes will be observed
Explanation: The outer maximum refers to the secondary peaks on both sides of the central maximum in the interference pattern.
Correct answer: The width of the outer maximum is decreased- A. Transverse waves
- B. Longitudinal waves
- C. Mechanical waves
- D. None of these
Explanation: The phenomenon of polarization of light reveals that light waves are transverse waves.Transverse waves are characterized by vibrations…
Correct answer: Transverse waves- A. 0.30 mm
- B. 0.30 cm
- C. 0.30 nm
- D. 0.30 m
Explanation: The explanation is given below:In a double slit experiment, the position of the mth order maximum can be determined using the formula:d ×…
Correct answer: 0.30 mm- A. 1,553 wavelengths of red light
- B. 1,553 wavelengths of blue light
- C. 1,553,163.5 wavelengths of red light
- D. 1,553,163.5 wavelengths of blue light
Explanation: Michelson measured the length of the standard meter in terms of the wavelength of red cadmium light and showed that the standard meter was…
Correct answer: 1,553,163.5 wavelengths of red light- A. sin(30) / sin(45)
- B. sin(45) / sin(30)
- C. sin(60) / sin(45)
- D. sin(45) / sin(60)
Explanation: The explanation is given below:To calculate the refractive index of medium Q, we can use Snell's law, which relates the angles of…
Correct answer: sin(45) / sin(30)- A. A medium which absorbs light
- B. A medium which absorbs polarized light
- C. A medium which can rotate the plane of polarization
- D. A medium which refracts polarized light
Explanation: An optically active medium can rotate the plane of polarization of a beam of light that is passed through it.
Correct answer: A medium which can rotate the plane of polarization- A. Width of central maxima increases
- B. Width of central maxima does not change
- C. Central maxima becomes brighter
- D. Width of central maxima decreases
Explanation: From the equation shown below, it is clear that wavelength is directly proportional to the distance between the central maximum to the…
Correct answer: Width of central maxima increases- A. Interference of light
- B. Refraction of light
- C. Reflection of light
- D. Diffraction of light
Explanation: It works on the principle of interference of light by the division of amplitude in light from an extended source into two parts of equal…
Correct answer: Interference of light- A. Red light is used as compared to blue light
- B. X-ray is used as compared to blue light
- C. Violet light is used as compared to blue light
- D. Ultraviolet light is used as compared to blue light
Explanation: Fringe spacing is directly related to wavelength (because as the wavelength increases the angle of diffraction increases).Red light has…
Correct answer: Red light is used as compared to blue light- A. Non-interference fringes observed
- B. Only the central bright fringe is observed
- C. Only red and white fringes are observed
- D. Central bright and few colored fringes are observed
Explanation: A bright central fringe is formed due to all the colors and as the dispersion becomes less few other colored fringes are also observed on…
Correct answer: Central bright and few colored fringes are observed- A. 0˚
- B. Angle of incidence
- C. Twice the angle of incidence
- D. 90˚
Explanation: The critical angle is the angle of incidence to which the angle of refraction is equivalent to 90 ° .
Correct answer: 90˚- A. Radio waves
- B. Ultrasound
- C. Ultraviolet
- D. X-rays
Explanation: "Ultrasound" waves are longitudinal in nature, hence they cannot be polarized.
Correct answer: Ultrasound- A. 9I/4
- B. 3I/2
- C. 4I/9
- D. 2I/3
Explanation: I ∝ 1/d2 I=k/d2 I=k/(3x)2 k=9x2I eq (1)Now, Inew=k (2x)2Putting the value of k from eq (1) Inew= 9x2I / 4x2 Inew= 9 I / 4Hence,A is the…
Correct answer: 9I/4