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If a wave gets refracted into a denser medium, then which of the following is true?
Asked in JEE Main 27th June 2nd Shift 2022 · Snell's law, slabs and apparent depth
- (1) wavelength, speed and frequency decreases.
- (2) wavelength increases, speed decreases and frequency remains constant.
- (3) wavelength and speed decreases but frequency remains constant.
- (4) wavelength, speed and frequency increases.
Answer: (3) wavelength and speed decreases but frequency remains constant.
Step-by-step solution
Frequency is fixed by the source.
In a denser medium v=c/n decreases.
λ=v/f decreases too.
Why the other options are wrong
- (1) Frequency cannot change on refraction.
- (2) With v=fλ and fixed f, lower speed means lower wavelength.
- (4) Speed drops in a denser medium and frequency stays fixed.
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