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प्रश्न
A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 108 ms-1 and 230 nm respectively. The wavelength of light in the air will be ______.
पर्याय
230 nm
345 nm
460 nm
690 nm
उत्तर
A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 108 ms-1 and 230 nm respectively. The wavelength of light in the air will be 460 nm.
Explanation:
We know that,
Speed = Wavelength × Wave frequency
In this equation, the wavelength is measured in meters, and frequency is measured in hertz (Hz), or the number of waves per second.
Given: v2 (speed of medium) = `1.5 xx 10^8`, Wavelength (λ2) = 230 nm, speed of light in air (v1) = `3 xx 10^8` m/s
To find: Wavelength of air(λ1)
∴ `v_1/lambda_1 = v_2/lambda_2`
`3 xx 10^8 xx 230 = 1.5 xx 10^8 xx lambda_1`
`lambda_1 = 460` nm
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