Question

The radius of an arc having length $1$ astronomical unit (AU) which subtends an angle of $2$ seconds is?

• A. $1.63$ light year
• B. $3.26$ light year
• C. $1$ parsec
• D. $1.2$ light year

Answer 1

The correct option is A $1.63$ light year

Parsec is a unit of distance used in astronomy, equal to about 3.26 light years.

Radius of arc $d=\frac{1A.U}{\theta }$

$d=\frac{3.26lightyear}{2sec}$

$=1.63$ light year