The 6563,mathring{A} H_{alpha} line emitted b | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) Wavelength of the $H_{\alpha}$ line emitted by hydrogen,$\lambda = 6563\,\mathring{A} = 6563 	imes 10^{-10} \,m$.The redshift of the star is give

Vedclass · Accepted Answer

$6.87 	imes 10^{5} \,m/s$

Vedclass · Answer

(A) Wavelength of the $H_{\alpha}$ line emitted by hydrogen,$\lambda = 6563\,\mathring{A} = 6563 	imes 10^{-10} \,m$.The redshift of the star is given by $\Delta\lambda = \lambda' - \lambda = 15\,\mathring{A} = 15 	imes 10^{-10} \,m$.Speed of light,$c = 3 	imes 10^{8} \,m/s$.For a star receding from the Earth,the Doppler shift formula is $\frac{\Delta\lambda}{\lambda} = \frac{v}{c}$,where $v$ is the speed of the star.Rearranging for $v$,we get $v = c 	imes \frac{\Delta\lambda}{\lambda}$.Substituting the values: $v = (3 	imes 10^{8} \,m/s) 	imes \frac{15 	imes 10^{-10} \,m}{6563 	imes 10^{-10} \,m}$.$v = \frac{45 	imes 10^{8}}{6563} \approx 6.87 	imes 10^{5} \,m/s$.Thus,the speed with which the star is receding from the Earth is $6.87 	imes 10^{5} \,m/s$.

The $6563\,\mathring{A}$ $H_{\alpha}$ line emitted by hydrogen in a star is found to be redshifted by $15\,\mathring{A}$. Estimate the speed with which the star is receding from the Earth.

Similar Questions

$A$ star moves away from Earth at a speed of $0.8 c$ while emitting light of frequency $6 \times 10^{14} \text{ Hz}$. What frequency will be observed on the Earth (in units of $10^{14} \text{ Hz}$)? ($c$ is the speed of light)

$A$ spectral line $\lambda = 5000\ \mathring A$ in the light coming from a distant star is observed as $5200\ \mathring A$. What will be the recession velocity of the star?

With what speed should a galaxy move outward with respect to Earth so that the sodium-$D$ line at wavelength $5890 \ \mathring{A}$ is observed at $5896 \ \mathring{A}$? (in $\text{km/s}$)

For an observer on the earth, if a spectral line of wavelength $6600 \, \text{Å}$ emitted by a star is found to be red shifted by $22 \, \text{Å}$, then the star is

The time period of rotation of the sun is $25$ days and its radius is $7 \times 10^8 \ m$. The Doppler shift for the light of wavelength $6000 \ \mathring{A}$ emitted from the surface of the sun will be ...... $\mathring{A}$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module