In a cascade control system, the closed loop transfer function of the inner loop may be assumed to have a single time-constant $\tau$${_1}$. Similarly, the closed loop transfer function of the outer loop may be assumed to have a single time constant $\tau$${_2}$. The desired relationship between $\tau$${_1}$ and $\tau$${_2}$ in a well-designed control system is
- $\tau$${_1}$ is much less than $\tau$${_2}$
- $\tau$${_1}$ is equal to $\tau$${_2}$
- $\tau$${_1}$ is much greater than $\tau$${_2}$
- $\tau$${_1}$ is independent of $\tau$${_2}$