JNTU
JNTU B.Tech III CONTROL SYSTEMS Previous Question Paper (October - 2020 - R13)
Answer any five questions. All questions carry equal marks.
Main
Explain the difference between open loop and closed loop system.
Answer
An open-loop control system is one in which the control action is independent of the output. It does not have feedback, making it simple in construction, inexpensive, and stable, but it is highly sensitive to disturbances and parameter variations, and its accuracy depends on calibration.
A closed-loop control system, or feedback control system, is one in which the control action is dependent on the output. It compares the actual output with the desired reference input to generate an error signal, which is then used to adjust the system. While more complex, expensive, and potentially unstable, it offers higher accuracy, better disturbance rejection, and reduced sensitivity to parameter changes.
Write the characteristics of feedback.
Answer
Feedback provides several fundamental characteristics that improve system performance:
- Increased Accuracy: By comparing the output to the reference, feedback reduces the steady-state error.
- Reduced Sensitivity: It makes the system gain less sensitive to variations in component parameters and external disturbances.
- Improved Bandwidth: Feedback allows for a wider operating frequency range, improving the system's speed of response.
- Disturbance Rejection: It effectively suppresses the effects of noise and unwanted signals within the system.
- Stability Concerns: While feedback improves performance, it can introduce instability if not designed correctly, requiring careful selection of loop gain and phase margins.
Develop the mathematical modeling for the following system and find transfer function X1(s)/F(s) (Figure 1).
Answer
Sign in to view the complete answer paper.
Obtain the signal flow graph for the following system and find the transfer function using Mason’s Gain formula (Figure 2).
Answer
Sign in to view the complete answer paper.
Explain the operation of Synchro transmitter and receiver with necessary derivations.
Answer
Sign in to view the complete answer paper.
Draw the response of under damped second order system for unit step input and Explain Time domain specifications.
Answer
Sign in to view the complete answer paper.
Find the error constants and steady state errors for unit step, unit ramp and unit acceleration inputs for the unity feedback system with open loop transfer function.
Answer
Sign in to view the complete answer paper.
Using R-H criteria, determine stability for the system with characteristic equation Q(s) = s^6 + s^5 + 6s^4 + 5s^3 + 10s^2 + 5s + 6. Also comment on location of poles.
Answer
Sign in to view the complete answer paper.
Define phase margin, gain margin, phase cross over frequency and gain cross over frequency?
Answer
Sign in to view the complete answer paper.
Explain stability conditions using bode plot in control system.
Answer
Sign in to view the complete answer paper.