Doppler Effect in Light

Wavelength of light from moving star observed on the earth is found to decrease by $0.05\%$. Relative to earth, star is

Wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in hydrogen spectrum is $656\times {10}^{-9}\mathrm{ }\mathrm{m}$ whereas wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in the spectrum of a distant galaxy is 706 nm. Speed of galaxy w.r.t. earth is

If a star is moving towards the earth, then the lines are shifted towards

When the wavelength of light coming from a distant star is measured it is found shifted towards red. Then the conclusion is

An observer is moving with half the speed of light towards a stationary microwave source emitting waves at frequency $10 \mathrm{GHz}$. What is the frequency of the microwave measured by the observer? (Speed of light $=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$).

According to Hubble's law the red-shift (Z) of a receding galaxy and its distance $r$ from earth are related as $Z\propto r^n,$ then find $n.$

A spectral line of wavelength 0.59 µm is observed in the directions to the opposite edges of the solar disc along its equator. A difference in wavelength equal to $\left(∆\mathrm{\lambda }\right)8$ picometer is observed. Period of Sun's revolution around its own axis will be about

(Radius of sun $=6.95\times {10}^8$ m)

A plane electromagnetic wave of frequency ${\mathrm{w}}_0$ falls normally on the surface of a mirror approaching with a relativistic velocity $\mathrm{\upsilon }$ . Then frequency of the reflected wave will be $\left(\mathrm{g}\mathrm{i}\mathrm{v}\mathrm{e}\mathrm{n}\mathrm{ }\mathrm{\beta }=\frac{\mathrm{\upsilon }}{\mathrm{c}}\right)$

Doppler shift for the light of wavelength $6000\mathrm{ }\mathrm{Å}$ emitted from the sun is $0.04\mathrm{ }\mathrm{Å}$. If radius of the sun is $7\times {10}^8\mathrm{ }\mathrm{m}$ then time period of rotation of the sun will be

If the velocity of a galaxy relative to earth is $1.2\times {10}^6\mathrm{ }\mathrm{m}\mathrm{ }{\mathrm{s}}^{-1}$ then $\mathrm{\%}$ increase in wavelength of light from the galaxy as compared to the similar source on earth will be

A star is moving away from Earth and shift in spectral line of wavelength $5700\mathrm{ }\mathrm{Å}$ is $1.90\mathrm{ }\mathrm{Å}$ . Velocity of the star is

The wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in the hydrogen spectrum is found to be $6563\mathrm{ }\mathrm{Å}$ in the laboratory. If the velocity of the Milky way is $1.05\times {10}^6\mathrm{ }\mathrm{m}\mathrm{ }{\mathrm{s}}^{-1}$, then the wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in the spectrum of Milky way will be

Wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in hydrogen spectrum is $656\times {10}^{-9}\mathrm{ }\mathrm{m}$ whereas wavelength of ${\mathrm{H}}_{\mathrm{\alpha }}$ line in the spectrum of a distant galaxy is 706 nm. Speed of galaxy w.r.t. earth is

In a spectrum of light of a luminous heavenly body wavelength of a spectral line is found to be $4747\mathrm{ }\mathrm{Å}$ , but actual wavelength of line is $4700\mathrm{ }\mathrm{Å}$ . Relative velocity of heavenly body w.r.t. earth is

A star emitting radiations of wavelength $5000\mathrm{ }\mathrm{Å}$ is approaching earth with a velocity of $1.5\times {10}^6\mathrm{ }\mathrm{m}{\mathrm{s}}^{-1}$ . Change in wavelength of radiations as received on the earth is

Which of the following explain that all galaxies are receding from us?

An earth satellite emits a radio signal of frequency ${10}^8$ Hz. An observer on the ground detects beats between the received signal and a local signal also of frequency ${10}^8$ Hz. At a particular moment, the beat frequency is 2400 Hz. What is the component of satellite velocity directed towards earth at this moment?

An earth satellite emits a radio signal of frequency ${10}^8$ Hz. An observer on the ground detects beats between the received signal and a local signal of frequency ${10}^8$ Hz. At a particular moment, the beat frequency is 2400 Hz. What is the component of satellite velocity directed towards earth at this moment?

The apparent wavelength of the light from a star moving away from the earth is $0.2\%$ more than its actual wavelength. Then the velocity of the star is

A rocket is receding away from earth with velocity $= 0.2\mathrm{c}$.The rocket emit signal or frequency $4\times {10}^7 \mathrm{Hz}$. The apparent frequency of the signal produced by the rocket observed by the observer on earth will be