The open loop transfer function of a unity feedback control system is given as \(G\left( s \right) = \frac{{as + 3}}{{{s^2}}}\). The value of ‘a’ for which the system will have a phase margin of 45° is equal to
1
\(\frac{{\sqrt 2 }}{{\sqrt 3 }}\)
2
\(\frac{{\sqrt {\sqrt 2 } }}{{\sqrt 3 }}\)
3
\(\frac{1}{{\sqrt {\sqrt 2 } }}\)
4
\(\frac{{\sqrt 3 }}{{\sqrt {\sqrt 2 } }}\)
5
None of these