NTPC Paper

                                       NTPC Executive Trainee Placement Paper

1. Inverse laplace transform of 1/s2[d/ds(e-3s/s)] is ?

2. Lower useful input limit of a transducer is determined by?

3. Z-transform of 3n u(n).

4. No. of encirclements made about the origin of the nyquist plot of the open loop TF:1/[(s-1)(s+2)(s+3)].

5. For a radioactive sample which decays to 12.5% of its initial value in x days, the half life is given by____

6. For a repeater in a PCM cable identify the correct sequence of actions amongst threshold/equalization/etc.

7. O/P of a delta modulator when a ramp input is fed to it.

8. Creeping occurs in energy meters because?

9. Major cause of losses in a fibre optic cable: (dispersion/total internal refraction/presence of core and cladding)?

10. Which layer in the OSI model is concerned with printer buffering,etc: (network/session/transport)?

11. Relation between laplace and z-transform: s=z/ s=ln z/ s=( ln z/T) /?

12. Maximum and minimum probability error among ASK,PSK,FSK,DPSK etc

13. Which of the following is a non linear modulation scheme: PAM/QAM/PCM/?

14. Which photodetector has output affected by own intrinsic noise: (PN/APD/PIN/all).

15. Time response of system having transfer function 625/(s2+25) will be of the form?

16. In an ECG instrumentation amplifier the differential gain is provided by (1st stage/2nd stage/mismatched resistors/output stage.)?

17. EMG signals are of the order of ?

18. Computer assisted tomography is used for?

19. Which is an effective measure of the noise related performance of an amplifier:(SNR/noise ratio/thermal noise/shot noise.)

20. Distinction between FM and PM at high frequencies.

21. Which of these has the least propagation delay RTL/ECL/I2L/CMOS.

22. JFET can operate in (depletion/enhancement/both/none of the above modes.)?

23. Why is LCD preferred to LED.?

24. How will 0.6973 be displayed on 10 V range of a 4 ½ digit multimeter.?

25. In a twisted ring counter the initial count is 1000. after the 4th clock pulse its state will be?

26. For parity bit checking which of the following gates can be used XOR/NAND/OR/XNOR.

27. How does a radioactive level gauging system work?

28. A capacitive transducer measuring level works on the principle of change in distance between plates/change in dielectric strength/?

29. Reproducibility of measurements is called (accuracy/precision/linearity/none of these.)?

30. What happens when the RET instruction is encountered by 8085