Name : www.jntuworld.com Time : 15 Min.

Branch : II /I ECE Subject : ECA Lab H No.: Marks :

Answer all questions each question carries one mark. Answer must be one word or one sentence

1. What is the type of capacitor used in RC coupled amplifier for a) coupling two phases b) by pass emitter

Ans. Generally electrolytic capacitors are used

2. What is signal source used for experiment of an RC coupled amplifier and how much maximum voltage it could giveAns. A function generator with 1 MHz highest frequency 0-30 V P – P output is used in sine wave mode

3. What is the pin configuration on bread board used in the lab

Ans. In the bread boards there are two rows of horizontally shorted pin bank on top and bottom, there are vertically shorted rows of pins in two halfs up and down from the center of the bread board.

4. For Class – A amplifier How do you bring operating point of amplifier at center of supply voltageAns. By adjusting the value of resistor used from base to supply. If Vc < Vcc/2 base resistor is increased and if Vc > Vcc/2 it is decreased

5. What are the transistors used in complementary push pull experiment give type numberAns. A matched pair of NPN (CL100 or SL100) and PNP (CK100 or SK100) used. Matching can be done by testing above in diode position of DMM for same drop and HFE sockets of NPN, PNP for .

6. How do you determine AC power output in class A amplifier i.e., do you measure current or voltage and how?Ans. P-P voltage is measured using CRO since AC current cannot be measured.

7. How much current do you pass through reference zener in series regulated power supply experimentAns. Iz min approximately equal to 5 mA is used.

8. In shunt regulator how is the value of resistor between base and emitter of shunt transistor determinedAns. VBE = 0.7 V, Resistor between BE = 0.7 / Iz min. practically 100 is used

9. How do you determine Q of oil used in tuned amplifier experiment

Ans. Q = L /Rs where is Resonant frequency; R is series resistance of coil

10. What is the transistor used in shunt regulator and what is its Case style

Ans. NPN transistor SL100 is used the case style is TO2

11. Name one NPN and PNP transistors we have used in ECA lab

Ans. BC 107 NPN, CK 100 PNP

12. What ammeter do you need to measure DC power to class – C amplifier (DMM, Analog coil meter or Analog moving iron meter)

Ans. Analog coil meter

13. What is the input resistance of oscilloscope you have used

Ans. 1 M , 1 %

14. What is the lamp used on all instruments to show presence of mainsAns. In all modern equipment LED(Light emitting diode) is used in various colors

15. What is the color code for 1.2 M 10 % resistor

Ans. Brown, Red, Green, Silver

16. For connection on bed board did you use single strand or multi strand wire.Ans. single strand wire

17. How do you check a transistor in DMM

Ans. Transistor contains BE and CB diode junctions. These can be tested in DMM in diode check position. Positive lead of DMM gives positive voltage and black negative

18. Name the type of digital display on the DMM you have used in the lab

Ans. 3 ½ digit LCD display

19. What is the type of voltage stabilizer used in the lab to ensure constant AC power

Ans. Servo controlled voltage stabilizer with 5 KVA rating is used

20. What is the color code 820 5 %

Ans. Gray, Red, Brown, Gold

21. Show the polarity of zener diode by symbol along with its physical outline side by side diode

22. How do you adjust the input signal for class AB operationsAns. Input is adjusted for initially no distortion. Gradually it increased such that there is flattening on top or bottom.

23. When you touch CRO input by hand very large signal appears on screen. What signal is it?

Ans. The signal is 50 cycles mains (HUM) picked up by body

24. What is the resistance a good fuse show?

Ans. A good fuse shows 0 or very few resistance

25. What is the color code 680 K 20%Ans. Blue, Gray, Brown

1. Define depletion region of a diode?

the depletion region, also called depletion layer, depletion zone, junction region or the

space charge region, is an insulating region within a conductive, doped semiconductor

material where the mobile charge carriers have diffused away, or have been forced away by

an electric field. The only elements left in the depletion region are ionized donor or acceptor

impurities.

2. What is meant by transition & space charge capacitance of a diode?

3. Is the V-I relationship of a diode Linear or Exponential?

4. Define cut-in voltage of a diode and specify the values for Si and Ge diodes?

5. What are the applications of a p-n diode?

6. Draw the ideal characteristics of P-N junction diode?

7. What is the diode equation?

8. What is PIV?

9. What is the break down voltage?

10. What is the effect of temperature on PN junction diodes?

VIVAQUESTIONS:-

1. What type of temp? Coefficient does the zener diode have?

2. If the impurity concentration is increased, how the depletion width effected?

3. Does the dynamic impendence of a zener diode vary?

4. Explain briefly about avalanche and zener breakdowns?

5. Draw the zener equivalent circuit?

6. Differentiate between line regulation & load regulation?

7. In which region zener diode can be used as a regulator?

8. How the breakdown voltage of a particular diode can be controlled?

9. What type of temperature coefficient does the Avalanche breakdown has?

10.By what type of charge carriers the current flows in zener and avalanche

breakdown diodes?

VIVA QUESTIONS:

1. What is the range of α for the transistor?

2. Draw the input and output characteristics of the transistor in CB configuration?

3. Identify various regions in output characteristics?

4. What is the relation between α and β?

5. What are the applications of CB configuration?

6. What are the input and output impedances of CB configuration?

7. Define α(alpha)?

8. What is EARLY effect?

9. Draw diagram of CB configuration for PNP transistor?

10. What is the power gain of CB configuration?

VIVA QUESTIONS:

1. What is the range of β for the transistor?

2. What are the input and output impedances of CE configuration?

3. Identify various regions in the output characteristics?

4. what is the relation between α and β

5. Define current gain in CE configuration?

6. Why CE configuration is preferred for amplification?

7. What is the phase relation between input and output?

8. Draw diagram of CE configuration for PNP transistor?

9. What is the power gain of CE configuration?

10. What are the applications of CE configuration?

11.VIVA QUESTIONS:

12. 1. What is the PIV of Half wave rectifier?

13. 2. What is the efficiency of half wave rectifier?

14. 3. What is the rectifier?

15. 4. What is the difference between the half wave rectifier and full wave

16. Rectifier?

17. 5. What is the o/p frequency of Bridge Rectifier?

18. 6. What are the ripples?

19. 7. What is the function of the filters?

20. 8. What is TUF?

21. 9. What is the average value of o/p voltage for HWR?

22. 10. What is the peak factor?

VIVA QUESTIONS:-

1. Define regulation of the full wave rectifier?

2. Define peak inverse voltage (PIV)? And write its value for Full-wave rectifier?

3. If one of the diode is changed in its polarities what wave form would you get?

4. Does the process of rectification alter the frequency of the waveform?

5. What is ripple factor of the Full-wave rectifier?

6. What is the necessity of the transformer in the rectifier circuit?

7. What are the applications of a rectifier?

8. What is ment by ripple and define Ripple factor?

9. Explain how capacitor helps to improve the ripple factor?

10.Can a rectifier made in INDIA (V=230v, f=50Hz) be used in USA (V=110v,

f=60Hz)?

VIVA QUESTIONS:

1. What are the advantages of FET?

2. Different between FET and BJT?

3. Explain different regions of V-I characteristics of FET?

4. What are the applications of FET?

5. What are the types of FET?

6. Draw the symbol of FET.

7. What are the disadvantages of FET?

8. What are the parameters of FET?

VIVA QUESTIONS:

1. What are the h-parameters?

2. What are the limitations of h-parameters?

3. What are its applications?

4. Draw the Equivalent circuit diagram of H parameters?

5. Define H parameter?

6. What are tabular forms of H parameters monoculture of a transistor?

7. What is the general formula for input impedance?

8. What is the general formula for Current Gain?

9. What is the general formula for Voiltage gain?

VIVA QUESTIONS:

1. What is phase difference between input and output waveforms of CE amplifier?

2. What type of biasing is used in the given circuit?

3. If the given transistor is replaced by a p-n-p, can we get output or not?

4. What is effect of emitter-bypass capacitor on frequency response?

5. What is the effect of coupling capacitor?

6. What is region of the transistor so that it is operated as an amplifier?

7. How does transistor acts as an amplifier?

8. Draw the h-parameter model of CE amplifier?

9. What type of transistor configuration is used in intermediate stages of a multistage

amplifier?

10.What is Early effect?

VIVA QUESTIONS:

1. What are the applications of CC amplifier?

2. What is the voltage gain of CC amplifier?

3. What are the values of input and output impedances of the CC amplifier?

4. To which ground the collector terminal is connected in the circuit?

5. Identify the type of biasing used in the circuit?

6. Give the relation between α, β and γ.

7. Write the other name of CC amplifier?

8. What are the differences between CE,CB and CC?

9. When compared to CE, CC is not used for amplification. Justify your answer?

10.What is the phase relationship between input and output in CC?

VIVA QUESTIONS:

1) What is the necessity of cascading?

2) What is 3dB bandwidth?

3) Why RC coupling is preferred in audio range?

4) Which type of coupling is preferred and why?

5) Explain various types of Capacitors?

6) What is loading effect?

7) Why it is known as RC coupling?

8) What is the purpose of emitter bypass capacitor?

9) Which type of biasing is used in RC coupled amplifier?

VIVA QUESTIONS

1. What is the difference between FET and BJT?

2. FET is unipolar or bipolar?

3. Draw the symbol of FET?

4. What are the applications of FET?

5. FET is voltage controlled or current controlled?

6. Draw the equivalent circuit of common source FET amplifier?

7. What is the voltage gain of the FET amplifier?

8. What is the input impedance of FET amplifier?

9. What is the output impedance of FET amplifier?

10.What are the FET parameters?

11.What are the FET applications?

VIVA QUESTIONS:

1. Give the formula for frequency of oscillations?

2. What is the condition for wien bridge oscillator to generate oscillations?

3. What is the total phase shift provided by the oscillator?

4. What is the function of lead-lag network in Wein bridge oscillator?

5. which type of feedback is used in Wein bridge oscillator

6. What is gain of Wein bridge oscillator?

7. what are the application of Wein bridge oscillator

8. What is the condition for oscillations?

9. What is the difference between damped oscillations undamped Oscillations?

Wein bridge oscillator is either LC or RC oscillator.

1. What are the conditions of oscillations?

2. Give the formula for frequency of oscillations?

3. What is the total phase shift produce by the RC ladder network?

4. Whether the oscillator is positive feedback or negative feedback?

5. What are the types of oscillators?

6. What is the gain of RC phase shift oscillator?

7. What is the difference between damped oscillations undamped oscillations?

8. What are the applications of RC oscillations?

9. How many resistors and capacitors are used in RC phase shift network

10.How the Barkhausen criterion is satisfied in RC phase shift oscillator

VIVA QUESTIONS

1. What is the effect of Current-Series Feedback amplifier on the input inmpedance of

the amplifier?

2. What is the effect of negative feedback on the Bandwidth of an amplifier?

3. State the reason for the usage of negative feedback in an amplifier?

4. What are the fundamental assumptions that are made in studying feedback

amplifiers?

5. What are the advantages of providing negative feedback amplifier?

6. What are the ideal characteristics of a voltage amplifier?\

7. Draw the circuit for the current series feedback?

8. What is the other name for current series feedback amplifier?

9. What is the formula for input resistance of a current series feedback?

10.What is the formula for output resistance of a current series feedback?

VIVA QUESTIONS

1. What is meant by Feedback?

2. What are the types of feedback amplifiers? Explain?

3. Draw the circuit for voltage series feedback?

4. What are the differences between positive and negative feedback?

5. What is the effect of negative feedback on gain of an amplifier?

6. What is the formula for voltage gain with negative feedback?

7. What are the other names for positive and negative feedback circuits?

8. What is the formula for input resistance of a voltage series feedback?

9. What is the formula for output resistance of a voltage series feedback?

10.VIVA QUESTIONS :

11.

12. 1. What are the applications of LC oscillations?

13. 2. What type of feedback is used in oscillators?

14. 3. What the expression for frequency of oscillations?

15. 4. Whether an oscillator is dc to ac converter?

16. 5. What is the loop gain of an oscillator?

17. 6. What is the difference between amplifier and oscillator?

18. 7. What is the condition for oscillations?

19. 8. How many inductors and capacitors are used in Hartley Oscillator?

20. 9. How the oscillations are produced in Hartley oscillator?

21.10. What is the difference between damped oscillations undamped oscillations?

VIVA QUESTIONS:

1. What are the applications of LC oscillators?

2. What type of feedback is used in oscillators?

3. What is the expression for the frequency of oscillations of colpitt’s oscillator?

4. Is an oscillator DC to AC converter?

5. What is the loop gain and loop phase shift of an oscillator?

6. How does colpitt’s differ from Hartley?

7. Which pair in circuit forms stabilizing circuit?

8. What is the function of input and output capacitor?

9. What is the condition for sustained oscillations in this oscillator?

10.Output capacitor acts as a?

11.Wha is the symbol of UJT?

12.Draw the equivalent circuit of UJT?

13.What are the applications of UJT?

14.Formula for the intrinsic stand off ratio?

15.What does it indicates the direction of arrow in the UJT?

16.What is the difference between FET and UJT?

17. Is UJT is used an oscillator? Why?

18.What is the Resistance between B1 and B2 is called as?

19.What is its value of resistance between B1 and B2?

20. Draw the characteristics of UJT?