In wave motion, the least distance between two points that are out of phase of π radians is:
Correct answer: D. λ/2
- A. λ
- B. 3λ
- C. 4λ
- D. λ/2
Explanation
In wave motion, the least distance between two points that are out of phase by π radians (180 degrees) is referred to as half of the wavelength (λ/2).The formula for phase difference (Δφ) in terms of wavelength (λ) is:Δφ = (path difference) / λFor two points that are out of phase by π radians:Δφ = π radiansSo, to find the path difference:π = (path difference) / λRearranging the formula to find the path difference:path difference = π * λSince we are looking for the least distance, this occurs when the path difference is equal to half of the wavelength:path difference = λ/2
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Classical physics cannot explain blackbody radiation and related observations, leading to Planck’s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
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