Consider the following statements:

1. The positiveness of coefficients of characteristic equation is necessary as well as sufficient condition for stability of first and second order systems.
2. The positiveness of coefficients of characteristic equation ensures negativeness of real roots but is not sufficient condition for stability of third and higher order systems.

Out of above statements:

For the transport lag G(jω) = e^-jωT, the polar plot is

For the signal flow graph of the given figure consider the following statements

1. It has three forward paths
2. It has three individual loops
3. It has two non touching loops

Out of above the correct statements are

The given figure shows a hybrid servosystem. The components 1, 2, 3, 4 are respectively

The polar plot of transport lag is a unit circle.