VLSIGURU INSTITUTE

WRITTEN TEST QUESTION ON BASIC ELECTRONICS – 3

1.     Explain the operation of diode using fermi level concept for forward bias and reverse bias?

2.     Write the diode current equation in forward bias and derive its resistance for small signal input?

3.     Explain Miller effect?

4.     Write the procedure of test for saturation region in BJT and explain with example?

5.     Explain the inverter operation using BJT?

6.     Explain the Basic current mirror circuit using MOSFET?

7.     What is uniform Doping and non-uniform doping and explain the significance?

8.     Explain how amplification is achieved in BJT using example?

9.     Explain briefly about working of N-channel JFET?

10.                         Explain briefly about working of N-channel depletion mode MOSFET?

11.                         Explain the significance of MOSFET as capacitor?

12.                         Explain briefly about schottky Diode?

13.                         Draw the 2- input NOR gate circuit using only NMOS?

14.                         Why Body (BULK) terminal is heavily doped compared to substrate in NMOS enhancement mode?

15.                         What happens to threshold voltage when gate oxide thickness is increased?

16.                         An N-channel enhancement MOSFET has threshold voltage = 2V and gate to source voltage = 1.2V. Find the region of operation if drain to source voltage is 4V?

17.                         An N-channel enhancement MOSFET has threshold voltage = 0.7V and gate to source voltage = 3V. Find the region of operation if drain to source voltage is 2V?

18.                         What are the disadvantages of the NMOS inverter with resistive load?

19.                         Draw the circuit of CMOS AND gate write the truth table?

20.                         What is short circuit current and leakage current in CMOS inverter?

21.                         Explain briefly about CZOCHRALSKI method?

22.                         What is difference between Dry and Wet oxidation?

23.                         What is isolation in VLSI fabrication and name the different isolation methods?

24.                         Explain briefly about Silicon on insulator (SOI)?

25.                         Define Sheet resistance and write formula?

26.                         What is diffusion process in VLSI fabrication and name the different techniques?

27.                         What is Photolithography and explain its steps briefly?

28.                         What is difference between positive photoresist and negative photoresist?

29.                         Explain briefly about Velocity saturation?

30.                         Explain length of diffusion and how to overcome?