It is defined by the ratio of Laplace transform of output response to Laplace transform of input (excitation) assuming all the initial conditions to be zero. Fig. 5.1(a) depicts the system in time domain whereas Fig. 5.1 (b) shows the system in Laplace domain.
Fig. 5.1 Transfer function of a system
If G(s) be the transfer function of the system, we can write mathematically
Example 5.1 Determine the transfer function of Fig. E5.1 vi (t) is the input to the system and v0(t) is the output of the system.