What is the approximate speed of light in a vacuum?
Correct answer: B. 3 × 10⁸ m/s
- A. 3 × 10⁶ m/s
- B. 3 × 10⁸ m/s
- C. 3 × 10¹⁰ m/s
- D. 3 × 10⁵ m/s
Explanation
Light travels at approximately 3 × 10⁸ metres per second in a vacuum — about 300,000 kilometres per second. This is the maximum speed at which any information can travel, and light slows down in denser media such as glass or water.
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About Optics
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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