The block diagram of a feedback control system is shown in the figure. The overall closed – loop gain G of the system is

\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2}{{\rm{H}}_1}}}\)

\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{H}}_1}}}\)

\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2} + {{\rm{G}}_1}{{\rm{H}}_1}}}\)

\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2} + {{\rm{G}}_1}{{\rm{G}}_2}{{\rm{H}}_1}}}\)

The block diagram of a feedback control system is shown in the figure.

1.	The block diagram of a feedback control system is shown in the figure. The overall closed – loop gain G of the system is
A.	\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{H}}_1}}}\)
B.	\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2} + {{\rm{G}}_1}{{\rm{H}}_1}}}\)
C.	\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2}{{\rm{H}}_1}}}\)
D.	\({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2} + {{\rm{G}}_1}{{\rm{G}}_2}{{\rm{H}}_1}}}\)
Answer» C. \({\rm{G}} = \frac{{{{\rm{G}}_1}{{\rm{G}}_2}}}{{1 + {{\rm{G}}_1}{{\rm{G}}_2}{{\rm{H}}_1}}}\)