Class 12 Physics Important Chapter 10 Wave Optics

Class 12 Physics Important Chapter 10 Wave Optics Solutions English Medium As Per The New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 12 Physics Additional Solutions in English and select need one. NCERT Class 12 Physics Additional Solutions Download PDF. HS 2nd Year Physics Important Solutions.

Class 12 Physics Important Chapter 10 Wave Optics

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 12 Physics Additional Question Answer are part of All Subject Solutions. Here we have given HS 2nd Physics Important Solutions English Medium for All Chapters, You can practice these here.

Wave Optics

Chapter: 10

IMPORTANT QUESTION AND ANSWER

Answer The Following Questions:

1. What type of wavefront will emerge from a (i) point source, and (ii) distant light source ?

Ans. (i) Spherical wavepoint from a point source.

(ii) Plane wavepoint from a distant source.

2. State Huygen’s principle.

Ans. According to Huygen’s principle:

(i) Each point on a wavefront becomes a fresh source of secondary wavelets, which spread out with the speed of light in that medium.

(ii) The new wavefront at any later time is given by the forward envelope of the secondary wavelets at that time.

3. Explain how you will distinguish between the unpolarised and linearly polarised light beams using a polaroid.

Ans. When a linearly polarised light is viewed through a polaroid the intensity of the light changes when the polaroid is about its own axis kept perpendicular to the direction of light. But in case of unpolarised light the intensity of light does not change even on rotating the polaroid.

4. Why does a soap bubble show beautiful colours when illuminated by which light? 

Ans: Light waves reflected from the upper and lower surfaces of a thin film interfere. Since the conditions for bright and dark fringes are satisfied at different positions for different wavelengths, so coloured fringes are observed.

5. State two conditions to obtain sustained interference of light.

Ans. (i) The two light sources should be coherent.

(ii) The two light sources should be narrow and placed close to each other.

6. State Brewster’s law.

Ans. According to Brewster’s law, when unpolarised light is incident at polarising angle, i,, on an interface separating air from a medium of refractive index μ, then: μ = tan i_p

7. Which quantity associated with light wave sets the limit of ability to distinguish very close objects?

Ans: The wavelength of light is the quantity that sets the limit on the ability to distinguish very close objects. This is because the resolving power of an optical instrument is inversely proportional to the wavelength of the light used. Shorter wavelengths provide better resolution.

8. H ₂O is a polar/non-polar molecule.

 Ans: H₂O (water) is a polar molecule. This is because it has a bent structure due to the lone pairs on the oxygen atom, and the difference in electronegativity between hydrogen and oxygen creates a dipole moment.

9. What is oil immersion objective?

Ans: An oil immersion objective is a microscope lens designed to be used with immersion oil between the lens and the cover slip. This reduces refraction and increases resolution by improving light gathering and matching the refractive index.

10. When are two sources said to be coherent?

Ans: Two sources are said to be coherent if they emit light waves that have the same frequency and a constant phase difference.

11. In Young’s double slit experiment, two slits are made one millimeter apart and the screen is placed one meter away. What is the fringe separation when a monochromatic light of wavelength 500 nm is used?

Ans: Given:

d = 1 mm = 1×10⁻³ m

D = 1 m

λ = 500 nm = 5 × 10⁻⁷ m