Questions on DIODE, BJT, MOSFET

 Questions on DIODE, BJT, MOSFET

 

 1.Compare PN Junction diode and Zener diode.

Ans: PN Junction diode

(i)   It is a lightly doped diode

(ii) Avanlanche breakdown occurs

         Zener diode

(i)   It is a heavily doped diode

(ii) Zener breakdown occurs

2.Name the three configurations of BJT

Ans: 1. Common Base Configuration

        2. Common Emitter Configuration

        3. Common Collector Configuration

3. What are the operating modes of MOSFET

Ans: 1. Enhancement Mode MOSFET

         2. Depletion Mode MOSFET

4. Define Rectifier

Ans: It is a circuit which converts AC voltage to unidirectional DC voltage

5. List three operating regions of BJT

Ans: 1. Active region

         2. Saturation region

         3. Cut-Off region

6. What are the operating modes of Op-Amp?

Ans: 1. Inverting Mode

         2. Non- Inverting Mode

         3. Differential Mode

7. Compare BJT and JFET

Ans: BJT

1.       Conduction is due to both majority and minority charge carriers

2.       It is a current controlled device

JFET

1.       Conduction is due to only majority charge carriers

2.       It is a voltage controlled device

        8. Compare JFET and MOSFET

        Ans: JFET

1.       It is operated in depletion mode

2.       Input resistance is low

MOSFET

1.       It is operated in enhancement and depletion mode

2.       Input resistance is high

        9. What are the ideal characteristics of Op-Amp

        Ans: Input resistance = infinity

                  Gain= infinity

                  Bandwidth= infinity

                  CMRR= infinity

                  SVRR= infinity

                  Output resistance=zero

     

        10. Define Amplifier

       Ans: A circuit that increases the amplitude of given input signal is called amplifier.

       11. Define Slew rate

       Ans: It is the maximum rate of change of output voltage per unit time.

       12. Define Common Mode Rejection Ratio

       Ans: The ratio of differential gain to common mode gain

       13. What are the DC characteristics of Op-Amp

       Ans: 1. Input Bias current

                2. Input Offset current

                  3. Input Offset voltage

                  4. Thermal Drift

       14. What are the AC characteristics of Op-Amp

       Ans: 1. Slew Rate

                2. Frequency Response

       15. What are the characteristics of CE Amplifier

       Ans: 1. Current gain is high

                   2. Voltage gain is high

                   3. Input resistance is medium

                   4. Output resistance is moderately high

                   5. Voltage phase shift is 180⁰

16. Mention three coupling schemes used in multistage amplifiers

Ans: 1. Resistance-Capacitance Coupling

         2. Transformer Coupling

          3. Direct Coupling

         17. Define Thermal Runaway in transistor

Ans: The self destruction of unstabilized transistor is known as Thermal Runaway

18. List three biasing techniques of transistor

Ans: 1. Fixed bias

         2. Collector to Base bias

         3. Voltage divider bias

19. Define operating point of transistor

Ans: The zero signal values of I_C and V_CE are known as operating point.

20. What is diode current equation in PN junction diode

Ans: 

         

         21. Define drain resistance in JFET

         Ans: It is defined as the ratio of small change in drain to source voltage to the corresponding

                  change in drain current at constant gate to source voltage.

22. What are the operating regions of JFET

Ans: 1. Ohmic region

         2. Pinch-Off region

         3. Breakdown region

23. Give the drain current equation of JFET

Ans:

 

 

24. Define ripple factor in rectifiers

Ans: The ratio of rms value of ac component to the dc component in the rectifier output is known

         as ripple factor.

25. Define peak inverse voltage

Ans: The maximum reverse voltage that a diode can withstand without destroying its junction.