JEE Mains · Physics · STD 12 - Wave optics
- JEE Mains 2022
- Medium
- MCQ
For a specific wavelength \(670 \; nm\) of light coming from a galaxy moving with velocity \(v\), the observed wavelength is \(670.7 \; nm\). The value of \(v\) is ............
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) \(3.13 \times 10^{5} \; ms ^{-1}\)
Step-by-step Solution
Detailed explanation
\(\lambda_{\text {emitted }}=670 \; nm\)
\(\lambda_{\text {obs }}=670.7 \; nm\)
\(v =?\)
\(c =3 \times 10^{8} \; m / s\)
If \(v << c\)
\(\frac{\lambda_{\text {obs }}-\lambda_{\text {emitted }}}{\lambda_{\text {emiited }}}=\frac{ v }{ c }\)
\(\frac{670.7-670}{670}=\frac{ v }{ c }\)
\(V =3.13 \times 10^{5} \; m / s\)
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