Question

The term used to describe the Doppler shift in wavelength of light emitted by a star moving away from the Earth is:

A. Longitudinal shift

B. Transverse shift

C. Redshift

D. Blueshift

Answer 1

The term for the Doppler shift of light from a star moving away from Earth is 'Redshift'. It refers to the stretching of the light to longer wavelengths, shifting toward the red part of the spectrum, while 'Blueshift' describes light from sources moving towards us shifting to shorter wavelengths.

Step-by-step explanation:

The term used to describe the Doppler shift in wavelength of light emitted by a star moving away from the Earth is C. Redshift. When a star or any other light source moves away from an observer, there is an increase in the wavelength of the observed light. This effect, which is a result of the Doppler effect, shifts the light toward the red end of the visible spectrum. Conversely, when the source moves toward the observer, the wavelength decreases, leading to a blueshift.

Astronomers utilize these terms not just for visible light but for all forms of electromagnetic radiation, including radio waves and X-rays. The change in wavelength is caused by the relative motion of the source and the observer, which is captured in the concept of relativistic Doppler effects. This concept is particularly significant in the study of the universe's expansion, where redshift plays a critical role in indicating that distant galaxies are moving away from us.

Answer 2

Option (C)

Step-by-step explanation:

In the field of astronomy, the redshift is defined as the shifting of the wavelength of light towards the red color of the spectrum. It describes about how the universe is expanding in every direction. The scientists have observed that the light in the universe emitted from distant objects such as the stars and galaxies is redshifted. This provides an example of Doppler's effect that is generally defined as the change in the wavelength of a wave that occurs when an observer moves relative to the source of the wave.

Hence, the correct answer is option (C).