UNIT - I Short Question and Answers 

Linear wave shaping

1.Define  linear wave shaping.

Ans: The process which by the wave form of a non-sinusoidal signal is altered by transmitting the signal through a linear network is termed as linear wave shaping.

2. Define linear network.

Ans: A network comprising of linear elements is called linear network.

3.What are the linear elements and why they called as linear elements.

Ans: Resistor, capacitor and inductor are linear elements since the current passing through them is proportional to the voltage i.e. there is linear relation between the applied voltage and resulting current.

4.Define time constant of RC circuit.

Ans: Time constant of the RC circuit is the time required for the output voltage (voltage across the capacitor) to attain 63.2% of the final steady value.

5. When the capacitor voltage becomes equal to the steady state value.

Ans:After 5 time constants, the capacitor voltage becomes equal to steady state value (99.3% of V)

6. why the high pass RC circuit called as RC differntiator.

  Ans: At RC<<T the high pass RC output is proportional to the time derivative of the input,hence it is called RC differentiator. This circuit finds useful application in converting a triangular wave into square wave.

7.How to minimize the distortion in RC high pass RC circuit with pulse input.

Ans:The time constant of the circuit must be very large as compared to the pulse width.

8.Define %tilt of RC circuit.

Ans:The decay in the amplitude of the output voltage wave due to the input voltage maintaining a constant level.

%Tilt   = 

X 100

9.Write the relation between f1 and %tilt.

Ans:  %tilt= (p/f).f1 X100

10.Define rise time

Ans: It is the time required for the voltage to rise from 10% to 90%  of the steady state value is termed as rise time.

tr= 2.2RC

11. Write the relation between rise and bandwidth.

Ans:  tr= 0.35/f2  or 0.35/Bandwidth

12. Write the general solution which represents the response of RC circuit.

Ans:  VO= Vfinal – (Vfinal – Vintial)

13.Define attenuator.

Ans: Attenuator is the circuit that reduces the amplitude of the signal without leading to any distortion in the signal waveform. Example: CRO probe.

14. Write the condition for perfect compensated attenuation

Ans: R1C1=R2C2

15.Write the time constant of RL circuit.

Ans:  t = L/R

16. When the decaying exponential 

 reaches 36.8% of its initial value.

Ans:  After one time constant

17. Write the damping constant of the RLC circuit.


18.Define ringing circuit.

Ans:  The RLC circuit which gives nearly undamped oscilloscopes is generally referred to as Ringing circuit.

19. Write the equation for cutoff  frequencies of Low pass and High pass RL circuits.

Ans:  Upper cut-off frequency  f2= 1/(2pL/R)  -low pass RL circuit

          Lower cut-off frequency f1=1/(2pL/R)- High pass RL circuit