Question

Find the value of one Au in 1000km.
A. $1.5\times {{10}^{5}}$ km
B. 2.5 $\times {{10}^{6}}$km
C. 1.5 $\times {{10}^{11}}$km
D. 2.5 $\times {{10}^{10}}$km

Answer 1

The full form of Au is an Astronomical unit. The value of the Astronomical Unit as distance is approximately 93 million miles, which is 150 million km. To cover an astronomical unit distance, light will take approximately 8 minutes.

Complete step by step answer:
The orbit, in which the earth moves around the Sun, is elliptical rather than a circle, which is uniform in distance. That is why, throughout a year the distance between sun and earth keeps changing. The Astronomical Unit represents the mean distance between earth and sun. In January we are 0.983 Astronomical unit away from the sun, while in July we are 1.017 Astronomical unit away from the Sun. Nowadays, the mean distances of all plants in our solar system from the sun are getting represented in Astronomical units.
Now, the value of the Astronomical unit is 150 million kilometer or $1.5\times {{10}^{8}}$km. Now, if we convert this in the form of 1000km, it will be $1.5\times {{10}^{5}}$ mega meter.

So, the correct answer is “Option A”.

Note:
Unit for measuring interstellar distances is light-year. If light moves around a whole year, the distance it covers is the measurement of light year. One light-year is equal to 64,320 Astronomical Unit.
The importance of the Astronomical Unit is, in our solar system, the Astronomical unit is more convenient for measurement in Astronomy or Astrophysics. Beyond our solar system, we mainly use Light-year as a measuring unit.
The Astronomical Unit can also be represented in terms of solar mass (M), one day time period (T) and Gaussian gravitational constant (k).