Q. One barn is equal to

1959 282 Physical World, Units and Measurements Report Error

A

$1 0^{- 30} m^{2}$

6%

B

$1 0^{28} m^{2}$

11%

C

$1 0^{- 28} m^{2}$

78%

D

$1 0^{30} m^{2}$

5%

Solution:

$1$ barn $= 1 0^{- 28} m^{2}$ .