UNIT-II short question and answers

Non linear wave shaping

1.What is non-linear wave shaping.

Ans: The wave shaping through the non-linear network is called non-linear wave shaping.

2.What is non-linear network.

Ans: A circuit consists of non-linear devices like diode , transistor and IC’s are called non-linear network.

3.Give the examples for non linear wave shaping  circuits.

Ans: Clipper  and clampers

4.Define clipper.

Ans: Clippers are used to remove the unwanted the portion of the wave form.

5.What are the different types of clippers.

  Ans:  Depends  on the non –linear device used clippers are classifies as

  1. Diode clippers and  2. Transistor clippers.

Diode clippers

Depends on the connection of diode in the circuit

Clippers are classified as 1. Series clippers   2.Shunt clippers.

Depends on the portion of the wave from selected for clipping clippers are classified as

1. Single level clippers

i).Series positive clippers with and without reference voltage

                                 ii).Shunt positive clippers with and without reference voltage

2. Two level clippers

Transistor clippers

1.Emitter coupled transistor clipper

2.Common emitter transistor clipper

6.What are the other names of the clippers.

Ans: Clippers are also called as voltage or current limiter or amplitude selectors  or slicers .

7.What are the applications of clippers.

Ans: Clippers are used to convert sine wave to square wave and used to remove the unwanted portion of the waveform.

8.What is the figure of merit for diodes used in clipping circuits.

Ans: The ratio of Rr/R­f  is the figure of merit of clipper.

9.What is comparator.

Ans: A comparator is a circuit used to mark the instant at which an arbitrary waveform attains a particular reference level.

10. What is the difference between the comparator and clipper?

Ans: In clipper the unwanted portion in the input is removed and the remaining portion is transmitted but in comparator there is no interest in reproducing any part of the waveform.

11.What are the applications of  voltage comparator.

Ans: In accurate time measurements, pulse time modulation, As timing markers generated from a sine wave, in phase meters, In amplitude distribution analyzers, to obtain square wave from sine wave, In analog to digital converters.

12.What do you mean by clamping.

Ans: Clamping circuits are used to clamp or fix the dc level of a periodic waveform to some constant reference level VR.

13. What are the other names of clamping circuits.

Ans: Clampers are also called DC restorer and DC reinserter.

14. Explain the operation of positive clamper (Negative peak clamper).

Ans: In positive clamper the negative peak of the input waveform is shifted to above DC reference level.

 15. Explain the operation of negative clamper (positive peak clamper).

Ans: In negative clamper the positive peak of the input waveform is shifted to above DC reference level.

16.Explain the operation of positive clipper.

Ans: In positive clipper the positive peak is clipped only the negative peak is transmitted to output.

17.Explain the operation of negative clipper.

Ans: In negative clipper the negative peak is clipped only the positive peak is transmitted to output.

18. Explain the operation of two level clipper.

Ans: In two level clipper the signal clipped from above and below reference levels and transmitted the signal between two reference level.

19. State clamping circuit theorem.

Ans:  The clamping circuit theorem states that for any input wave form under steady state conditions, the ratio of the area Af under the output voltage curve in the forward direction to that area under in the reverse direction  Ar is equal to the ratio Rf /Rr  i.e.

                                                                Af / Ar  = Rf /R r

  • Created
    Jan 28, 2016
  • Updated
    Feb 01, 2016
  • Views
    12,654