# Home / ECE / Signals and Systems :: Section 1

### ECE :: Signals and Systems

1. What about the stability of system in 2.  A. system is stable B. unstable C. stable at 0.4 D. cant say   3. Which one most appropriate dynamic system?

4.  A. y(n) + y(n - 1) + y(n + 1) B. y(n) + y(n - 1) C. y(n) = x(n) D. y(n) + y(n - 1) + y(n + 3) = 0   5. An energy signal has G(f) = 10. Its energy density spectrum is

6.  A. 10 B. 100 C. 50 D. 20   7. Consider Pole zero diagram as shown, If two Poles are moved in opposite direction towards ω = p/2 and -p/2, the filter will be 8.  A. change to high pass filter B. change to Band Pass filter C. remains same D. change to LPF   9. In an ac circuit the fundamental component of current wave lags the corresponding voltage wave by 20°. The third harmonic component of current wave lags the corresponding voltage by an angle.

10.  A. less than 20° B. more than 20° C. equal to 20° D. equal to or more than 20°   11. If and A + B is

12.  A. B. C. D.    13. A first order system will never be able to give a __________ response

1. band stop
2. band pass
3. all pass
Choose the correct option

14.  A. 1, 2, 3 true B. 1 and 3 true, 2 false C. 1, 2 are true 3 is false D. 1, 2 are false, 3 is true   15. In the given figure the ratio T/d is the duty factor. 16.  A. True B. False   17. If £[f(t)] = F(s), then £[f(t - T)] =

18.  A. est F(s) B. e-st F(s) C. D.    19. The z-transform of a particular signal is given where The system after implementation will be

20.  A. casual and stable B. non-casual and stable C. non-casual and unstable D. casual and unstable   