If block diagrams of the given figure (a) and (b) are to be equivalent, then

Consider the following statements:

1. If any root of characteristic equation has a positive real part the impulse response is unbounded and system is unstable.
2. If all the roots of a characteristic equation have negative real parts, the impulse response decays to zero.
3. If one or more non-repeated roots of characteristic equation are on jω axis impulse response is bounded but the system is unstable.

Which of the above equations are correct?

Consider the following statements about transport-lag

1. It is of non-minimum phase behaviour
2. It normally exists in thermal, hydraulic and pneumatic systems
3. It has an excessive phase lag with no attenuation at high frequency

Which of the above statements are correct?

Assertion (A): An on off controller gives rise to oscillation of the output between two limits.

Reason (R): Location of a pair of poles on jω axis gives rise to self sustained oscillations in the output.

Consider the following statements

1. The effect of feedback is to reduce system error
2. Feedback increases the system gain at one frequency but reduces the system gain as another frequency
3. Feedback can cause an originally stable system to become unstable

Which of the above statements are correct?