Define coherent sources. Can two independent sodium lamps be coherent?
Solution and Explanation
Coherent Sources
Definition of Coherent Sources
Two sources are said to be coherent if they emit light waves of the same frequency, wavelength, and constant phase difference.
Explanation
Two independent sodium lamps cannot act like coherent sources because their emissions are not phase-locked, and their phases vary randomly over time.
Top Questions on Wave Optics
Show the refraction of light wave at a plane interface using Huygens' principle and prove Snell's law.
- CBSE CLASS XII - 2025
- Physics
- Wave Optics
- Distinguish between interference and diffraction of light. A double slit arrangement produces interference fringes for sodium light of wavelength 589 nm, that are 0.20 degree apart. What is the angular fringe separation if the entire arrangement is immersed in water? (R.I. of water = 1.33)
- What is Brewster's law? Derive the formula for Brewster's angle.
- Calculate the de Broglie wavelength of an electron moving with a given velocity.
- BITSAT - 2025
- Physics
- Wave Optics
- Define a wavefront. An incident plane wave falls on a convex lens and gets refracted through it. Draw a diagram to show the incident and refracted wavefront.
- CBSE CLASS XII - 2025
- Physics
- Wave Optics
Questions Asked in CBSE CLASS XII exam
- Let the polished side of the mirror be along the line \[ \frac{x}{1} = \frac{1 - y}{2} = \frac{2z - 4}{6}. \] A point \( P(1, 6, 3) \), some distance away from the mirror, has its image formed behind the mirror. Find the coordinates of the image point and the distance between the point \( P \) and its image.
- CBSE CLASS XII - 2025
- 3D Geometry
- Find : \[ I = \int \frac{x + \sin x}{1 + \cos x} \, dx \]
- CBSE CLASS XII - 2025
- Integration
- A charge \( -6 \mu C \) is placed at the center B of a semicircle of radius 5 cm, as shown in the figure. An equal and opposite charge is placed at point D at a distance of 10 cm from B. A charge \( +5 \mu C \) is moved from point ‘C’ to point ‘A’ along the circumference. Calculate the work done on the charge.
- CBSE CLASS XII - 2025
- Electrostatics
From the following information, calculate Opening Trade Receivables and Closing Trade Receivables :
Trade Receivables Turnover Ratio - 4 times
Closing Trade Receivables were Rs 20,000 more than that in the beginning.
Cost of Revenue from operations - Rs 6,40,000.
Cash Revenue from operations \( \frac{1}{3} \)rd of Credit Revenue from operations
Gross Profit Ratio - 20%- CBSE CLASS XII - 2025
- Ratio analysis
Draw a rough sketch for the curve $y = 2 + |x + 1|$. Using integration, find the area of the region bounded by the curve $y = 2 + |x + 1|$, $x = -4$, $x = 3$, and $y = 0$.
- CBSE CLASS XII - 2025
- Integration