Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • The 6563 Å Hα line emitted by hydrogen in a star is found to be red- shifted by 15 Å. Estimate the speed with which the star is receding from the Earth.

Q10.11  The 6563 Å Hα line emitted by hydrogen in a star is found to be red-shifted by 15 Å. Estimate the speed with which the star is receding from the Earth.

Answers (1)

best_answer

Given,

wavelength  Hα line emitted by hydrogen:

\lambda=6563*10^{-10}m

star is  red-shifted by

 \lambda'-\lambda=15*10^{-10}m

let velocity of the star be v

Now,

as we know,

\lambda'-\lambda=\frac{v}{c}*\lambda

from here

\lambda'-\lambda\frac{1}{{c}*\lambda }={v}

v=\frac{3*10^8*15*10^{-10}}{6563*10^{-10}}=6.87*10^5m/s

Hence speed at which star is receding away is 6.87*10^5m/s

Posted by

Pankaj Sanodiya

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE board exams 2025 from February 15; Class 10, 12 subject-wise marks distribution
anam-khan

CBSE Date Sheet 2025: Class 10, 12 board exam dates soon on cbse.gov.in; previous trends, sample papers
anam-khan

CBSE Board Exams 2025: 75% attendance must for students to be eligible, reiterates board

Latest Question