The bode plot of the delay transfer function e-3s has the following shape 

This question was previously asked in
ISRO Scientist Electronics 2024 Official Paper
View all ISRO Scientist Papers >
  1. Straight line with negative slope
  2. Straight line with positive slope
  3. A curved line with resonance
  4. A curve with two straight parts

Answer (Detailed Solution Below)

Option 1 : Straight line with negative slope
Free
ISRO Scientist/Engineer Fluid Mechanics Mock Test
20 Qs. 20 Marks 25 Mins

Detailed Solution

Download Solution PDF

Concept:

The transfer function represents a pure time delay of T seconds.

When analyzing this in the frequency domain for Bode plots, we substitute :

This is a complex exponential which affects only the phase of the frequency response, not the magnitude.

Magnitude:

So the magnitude plot is a horizontal straight line at 0 dB.

Phase:

Phase decreases linearly with frequency. Specifically, for T = 3 seconds:

radians

In degrees:

This is a straight line with a negative slope in the phase plot.

Given:

Transfer function: e-3s (pure delay of 3 seconds)

Conclusion:

  • Magnitude plot: Constant at 0 dB (flat line)
  • Phase plot: Straight line with a negative slope (due to the increasing delay with frequency)

Latest ISRO Scientist Updates

Last updated on Jun 24, 2025

-> ISRO Scientist Engineering apply online 2025 link has been activated (ISRO:ICRB:03(CEPO):2025).

-> A total of 39 vacancies are announced for the ISRO recruitment in Civil, RAC and other disciplines

-> ISRO Scientist Engineering recruitment 2025 notification has been released for 320 vacancies. The last date to fill ISRO application form is June 16 (Advt No. ISRO:ICRB:02(EMC):2025).

-> ISRO Scientist Engineer recruitment 2025 for 31 vacancies has been released. 

->ISRO Scientist recruitment 2025 notification has been released. 

->The last date to apply for ISRO scientist recruitment 2025 is May 30 ( Advt.No. ISRO:ICRB:01:(EMC):2025). 

->Candidates with BE/BTech degree in the respective discipline can only apply for ISRO Scientist recruitment 2025. 

-> Candidates can refer ISRO Scientist previous year paper to prepare for the exam. 

More Frequency Response Analysis Questions

Hot Links: teen patti vip teen patti 50 bonus teen patti 100 bonus teen patti all game