JEE Mains · Physics · STD 12 - Wave optics
- JEE Mains 2021
- Hard
- Numerical
A galaxy is moving away from the earth at a speed of \(286\, kms ^{-1}\). The shift in the wavelength of a red line at \(630\, nm\) is \(x \times 10^{-10}\, m\). The value of \(x ,\) to the nearest integer, is........ [Take the value of speed of light \(c,\) as \(3 \times 10^{8}\) \(\left. ms ^{-1}\right]\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(6\)
Step-by-step Solution
Detailed explanation
\(\frac{\Delta \lambda}{\lambda} c=v\)
\(\Delta \lambda=\frac{v}{c} \times \lambda=\frac{286}{3 \times 10^{5}} \times 630 \times 10^{-9}=6 \times 10^{-10}\)
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