Free Optics MCQs with Answers

• A. Light travels in straight line
• B. Light travels in electromagnetic waves
• C. All points on primary wave front are source of secondary wavelets
• D. Light has dual nature

Explanation: Huygen's principle states that all points on the primary wavefront are sources of secondary wavelets that spread out in all directions.

• A. The sources should be monochromatic
• B. The sources should be phase coherent
• C. The linear superposition should be applicable
• D. All of these

Explanation: The correct answer is Option D: All of these. Monochromatic sources ensure a single wavelength for interference, phase coherence maintains…

• A. Newton
• B. Michelson
• C. Huygen
• D. Young

Explanation: The correct answer is Option B: Michelson. Albert A. Michelson accurately determined the velocity of light using his interferometer, a…

• A. Dispersion of light
• B. Diffraction of light
• C. Scattering of light
• D. Interference of light

Explanation: Soap film in sunlight appears colored due to the interference of light.

• A. Bright fringes are wider than dark fringes
• B. Dark fringes are wider than bright fringes
• C. Both dark and bright fringes are of equal width
• D. Central fringes are brighter than the outer

Explanation: Interference patterns exhibit a specific relationship between the widths of dark and bright fringes.

• A. Polarisation of light
• B. Different elements present in the oil
• C. Interference of light
• D. The transmission of light

Explanation: When light strikes the thin oil film on water, some of it is reflected from the top surface and some of it is reflected from the oil-water…

• A. Diffraction
• B. Reflection
• C. Interference
• D. Polarisation

Explanation: The appearance of colours in thin films is due to interference, where light waves interact either constructively or destructively leading…

• A. Diffraction of light
• B. Interference of light
• C. Polarisation of light
• D. Reflection of light

Explanation: Newton's rings are formed due to the interference of light. When a plano-convex lens is placed on a flat glass surface, a thin film of air…

• A. 10 A0
• B. 1000 A0
• C. 1 A0
• D. 100 A0

Explanation: X-rays have wavelengths in the range of 0.01 to 10 nanometers, which is approximately 1 Angstrom. This makes option C the correct answer.

• A. Corpuscular in nature
• B. Of extremely short waves
• C. Longitudinal waves
• D. Transverse waves

Explanation: Polarisation of light refers to the orientation of the oscillations of light waves.

• A. The magnetic field (H)
• B. The electric field (E)
• C. Both the electric and magnetic fields Hand (E)
• D. Frequency (f)

Explanation: The energy of a photon is directly proportional to its frequency, as described by Planck's formula E = hf, where h is Planck's constant.

• A. d = λ /2
• B. d = 3 λ /2
• C. d = 5 λ /2
• D. d = m λ

Explanation: For constructive interference to occur, the path difference between the two interfering waves must be an integer multiple of the…

• A. hf/c2
• B. hc2
• C. h/f
• D. h/c2

Explanation: The energy of a photon is given by the equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency of the…

• A. Find index of refraction
• B. Explain polarisation
• C. Locate the wave front
• D. Determine the speed of light

Explanation: Huygen's principle states that every point on a wavefront can be considered as a source of secondary wavelets that spread out in all…

• A. Frequency of light
• B. Wavelength of light
• C. Nature of the medium
• D. Temperature

Explanation: The index of refraction of a medium is primarily influenced by the nature of the medium itself.

• A. Blue
• B. Green
• C. Red
• D. Orange

Explanation: Complementary colors are pairs of colors that contrast with each other the most.

• A. Greater than that of red colour
• B. Less than that of red colour
• C. The same as that of red colour
• D. None of these

Explanation: When comparing the energy of photons, it is important to consider their wavelengths.

• A. Maxwell
• B. Newton
• C. Huygen
• D. Thomas Young

Explanation: Issac Newton laid the foundation of the theory 'corpuscular nature of light' through his work in optics.

• A. Thomas Young
• B. Huygen
• C. Newton
• D. Maxwell

Explanation: Thomas Young performed his famous double slit experiment which provided the experimental evidence in favour of the wave theory about the…

• A. Velocity
• B. Wavelength
• C. Amplitude
• D. Frequency

Explanation: Frequency does not depend on the nature of medium, as it remains the same in different mediums.