General Knowledge - Physics - Discussion

Discussion :: Physics - Section 1 (Q.No.54)


Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in

[A]. 4.2 seconds
[B]. 42 seconds
[C]. 4.2 years
[D]. 42 years

Answer: Option C


No answer description available for this question.

Hitro said: (May 26, 2011)  
Nearest to the earth after sun. wasnt it Proxima centauri?

K.S.Kiran(Ap Iiit Nuzid) said: (Apr 10, 2012)  
Alpha centauri is not a star but it is a star system which contains star Proxima centauri. Let me give you an example. Alpha centari is just like our solar system. Proxima centauri is star just like our the Sun. In Alpho centauri besides Proxima centauri there is another two stars. This is answer for Hitro question.

Vivetha.H said: (May 12, 2012)  
I need clear explanation than what you told.

Nitin said: (Aug 17, 2013)  
Alpha centauri is 4.37 light years from the Sun & after sun alpha centauri is nearest from the earth.

Hardik said: (Aug 29, 2013)  
Alpha centauri is 4.37 light years from the Sun & after sun alpha centauri is nearest from the earth.

Sahil said: (Sep 12, 2013)  
Common people it takes 8 min for light to travel from sun to earth therefore 1st two options are wrong. Now its obvious that 42 years is quite long time so therefore 4.2 is write option.

Pushkar said: (May 26, 2014)  
Nearest star to the sun is proxima centauri. Is it?

Rohit Bains said: (Nov 23, 2015)  
Sun light takes 8 min to reach earth, then why light of alpha century which is nearer, takes more time? Can any one explain?

Pavneet said: (Dec 11, 2015)  
No, the alpha centari is not nearer to alpha centari. Light comes from earth in 8.32 minutes as it is about 149000000 km.

i.e. 3*100000 (speed of light) 8.32*60 (time taken) {by using, distance = speed*time taken}.

You can guest what is the distance between earth and alpha centari.

Sarvanika said: (May 8, 2016)  
Thank you all for explaining the question.

Suma said: (Dec 9, 2016)  
I want clear explanation for this, please help me.

Nagaraj said: (Feb 19, 2018)  
@Rohit Bains.

The distance between the sun and earth is 149.6 million km and the distance between the earth and star is 9.46 million km. so that light from the stars takes more time to reach earth than the sun. And distance is also responsible for the twinkling of the stars, light from the starts gets refracted by air medium in the atmosphere layer. So stars may twinkle while we see.

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