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Q40 (NDA-II/2018) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Atomic and nuclear physics Answer Verified

Consider the following statements about visible light, UV light and x-rays : 1. The wavelength of visible light is more than that of X-rays 2. The energy of X-rays photons is higher than that of UV light photons. 3. The energy of UV light photons is less than that of visible light photons. Which of the statements given above is/are correct?

Result
Your answer: —  Â·  Correct: B
Explanation

The electromagnetic spectrum is organized by wavelength and frequency, where energy is inversely proportional to wavelength (E = hc/λ). Visible light has a wavelength range of approximately 400–700 nm. Ultraviolet (UV) light has a shorter wavelength range of 10–400 nm, and X-rays have even shorter wavelengths ranging from 0.01–10 nm. Consequently, statement 1 is correct as visible light wavelengths (400–700 nm) are significantly larger than X-ray wavelengths (0.01–10 nm). Statement 2 is also correct because X-rays, having shorter wavelengths than UV light, possess higher photon energy. However, statement 3 is incorrect; since UV light has shorter wavelengths (10–400 nm) than visible light (400–700 nm), UV photons actually possess higher energy than visible light photons. Therefore, only statements 1 and 2 are correct.

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