Calculate the effective neutron capture radius of a nucleus having a cross section of 1.0 barn.

Explanation

1.0 barn `= 1.0 xx 10^(24) cm^(2) = 10^(-28) m^(2)`
The area of a circle is given by `A = pi r^(2)`
Hence, `r = sqrt(A//pi)`
`= sqrt((1.0 xx 10^(-24) cm^(2))// 3.14)`
`= 5.6 xx 10^(-13) cm`