Question 107: Wave Optics

Question

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 :

Accepted Answer

${\lambda _{obs}} = {\lambda _{source}}\sqrt {{{1 + {v \over C}} \over {1 - {v \over C}}}} $
For $v <  < C$,
${{670.7} \over {670}} = 1 + {v \over C}$
$ \Rightarrow v = {{0.7} \over {670}} 	imes 3 	imes {10^8}$ m/s
$ \Rightarrow v \simeq 3.13 	imes {10^5}$ m/s

Answer

3 $	imes$ 10
8
ms
$-$1

Answer

3 $	imes$ 10
10
ms
$-$1

Answer

3.13 $	imes$ 10
5
ms
$-$1

Answer

4.48 $	imes$ 10
5
ms
$-$1

Wave Optics

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 :

Choose the correct answer: