Light and Optics
PART-A Unit-I: General Science
Previous Year Questions (PYQ) for this topic
Every TNPSC question asked from this topic, compiled as a PDF. · PDF 3.8 MB
Optics and Radiation - PYQ Points
1. Properties of Light
- Speed: No object in the universe can exceed the speed of light. When passing through glass, violet light travels at the lowest speed.
- Raman Effect: It is the scattering of light that occurs in pure liquids.
- Polarization: The angle of polarization is the angle at which the reflected ray becomes completely polarized. If the angle of incidence is 40°, then the angle of polarization is also 40°.
- Interference: The appearance of colors in soap bubbles is due to interference. However, the quantum theory of light does not explain the interference phenomenon.
- Spectrum: The Fraunhofer lines observed in sunlight are the best example of an absorption line spectrum.
2. Comparison of Doppler Effect
Doppler Effect in Light
Symmetric
Doppler Effect in Sound
Asymmetric
3. Lasers & X-Rays
- Laser: Laser beams are used in surgeries because they have a sharp focus. CO₂ laser is used for hair removal.
- X-Rays: Discovered by Röntgen. Their frequency ranges from 1017 to 1019 Hz.
4. Lenses and Colors
| Feature | Description |
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