Question

Which of the statement is correct with regard to the bandwidth of the control loop system:

(a) In systems where the low frequency magnitude in 0 dB on the bode diagram, the bandwidth is measured at the -3 dB frequency

(b) The bandwidth is the measurement of the accuracy of the closed loop system

(c) The stability is proportional to the bandwidth

(d) The system with larger bandwidth provides slower step response and lower fidelity ramp response

I got this question in an interview for internship.

The above asked question is from Feedback Compensation in section Design of Control Systems

Answer 1

Right choice is (a) In systems where the low frequency magnitude in 0 dB on the bode diagram, the bandwidth is measured at the -3 dB frequency

The best I can explain: Bandwidth is the frequency measured at the gain of 3dB and for the good control system the value of the bandwidth must be large but the large value of the bandwidth increses the noise in the system.