1. N – Type silicon is obtained by doping silicon with

a. Germanium

b. Aluminum

c. Boron

d. Phosphorous

2. The band gap of silicon at 300

a. 1.36 eV

b. 1.10 eV

c. 0.80 eV

d. 0.67 eV

3. The intrinsic carrier concentration of silicon sample at 300

a. 4.5 x 10

b. 3.3 x 10

c. 5 x 10

d. 3 x 10

4. Choose proper substitutes for X and Y to make the following statement correct.

Tunnel diode and Avalanche photo diode are operated in X bias and Y bias respectively.

a. X: Revere , Y: Reverse

b. X: Revere, Y: Forward

c. X: Forward, Y: Reverse

d. X: Forward, Y: Forward

5. For an N channel type MOSFET, if the source is connected at a higher potential than that of the bulk (i.e. V

a. Remain unchanged

b. Decrease

c. Change polarity

d. Increase

6. An N type silicon bar 0.1 cm long and µm

a. 10

b. 10

c. 10

d. 10

7. The electron concentration in a sample of uniformly doped N type silicon at 300

a. Zero

b. -112 A/cm

c. +1120 A/cm

d. -1120 A/cm

8. Match items in Group 1 with items in Group 2, most suitably,

9. At 300

a. 1

b. 5

c. 4 x 10

d. 8 x 10

10. A particular green LED emits light of wavelength 5490 A

a. 2.26 eV

b. 1.98 eV

c. 1.17 eV

d. 0.74 eV

11. When the gate to source voltage (V

a. 0.5 mA

b. 2.0 mA

c. 3.5 mA

d. 4.0 mA

12. If P is passivation, Q is n-well implant, R is metallization and S is source/drain diffusion, then the order in which they are carried out in a standard n-well CMOS fabrication process is

a. P-Q-R-S

b. Q-S-R-P

c. R-P-S-Q

d. S-R-Q-P

13. The action of a JFET in its equivalent circuit can best be represented as a

a. Current controlled current source

b. Current controlled voltage source

c. Voltage controlled current source

d. Voltage controlled voltage source

a. Germanium

b. Aluminum

c. Boron

d. Phosphorous

**Solutoin :**https://www.youtube.com/watch?v=VlGHV08XPHE2. The band gap of silicon at 300

^{0}K isa. 1.36 eV

b. 1.10 eV

c. 0.80 eV

d. 0.67 eV

**Solutoin :**https://www.youtube.com/watch?v=_NjNJR8cCEU

3. The intrinsic carrier concentration of silicon sample at 300

^{o}K is 1.5 x 10^{16}m^{-3}. If after doping, the number of majority carriers is 5 x 10^{20}m^{-3}, the minority carrier density isa. 4.5 x 10

^{11}/ m^{3}b. 3.3 x 10

^{4}/ m^{3}c. 5 x 10

^{20}/ m^{3}d. 3 x 10

^{-5}/ m^{3}**Solutoin :**https://www.youtube.com/watch?v=csUoP33C4k4

4. Choose proper substitutes for X and Y to make the following statement correct.

Tunnel diode and Avalanche photo diode are operated in X bias and Y bias respectively.

a. X: Revere , Y: Reverse

b. X: Revere, Y: Forward

c. X: Forward, Y: Reverse

d. X: Forward, Y: Forward

**Solutoin :**https://www.youtube.com/watch?v=GCy6rgwSBes

5. For an N channel type MOSFET, if the source is connected at a higher potential than that of the bulk (i.e. V

_{SB}> 0 volts), the threshold voltage V_{T}of the MOSFET willa. Remain unchanged

b. Decrease

c. Change polarity

d. Increase

**Solutoin :**https://www.youtube.com/watch?v=NkWeND6-BxI

6. An N type silicon bar 0.1 cm long and µm

^{2}in cross sectional area has a majority carrier concentration of 5 x 10^{20}m^{-3}and the carrier mobility is 0.13 m^{2}/V-sec at 300^{o}K. If the charge of an electron is 1.6 x 10^{-19}coulomb, then the resistance of the bar isa. 10

^{6}Ωb. 10

^{4}Ωc. 10

^{-1}Ωd. 10

^{-4}Ω**Solutoin :**https://www.youtube.com/watch?v=3y_xJwMihpo

7. The electron concentration in a sample of uniformly doped N type silicon at 300

^{o}K varies linearly from 10^{17}cm^{-3}at x = 0 µm to 6 x 10^{16}cm^{-3}at x = 2 µm. Assume a situation that electrons are supplied to keep this concentration gradient constant with time. If electronic charge is 1.6 x 10^{-19}coulomb and the diffusion constant D_{n}= 35 cm^{2}/sec, the current density in the silicon, if no electric field is present isa. Zero

b. -112 A/cm

^{2}c. +1120 A/cm

^{2}d. -1120 A/cm

^{2}**Solutoin :**https://www.youtube.com/watch?v=Y5ktNfyNHW0

8. Match items in Group 1 with items in Group 2, most suitably,

**Solutoin :**https://www.youtube.com/watch?v=O-KiCZLmIxo

9. At 300

^{o}K, for a diode current of 1 mA, a certain Germanium diode requires a forward bias of 0.1435 volts, where as a certain Silicon diode requires a forward bias of 0.718 volts. Under the conditions stated above, the closest approximation of the ratio of reverse saturation current in Ge to that of Si diode isa. 1

b. 5

c. 4 x 10

^{3}d. 8 x 10

^{3}**Solutoin :**https://www.youtube.com/watch?v=8mEekTAFoYU

10. A particular green LED emits light of wavelength 5490 A

^{o}. The energy band gap of the semiconductor material used there is (Plank’s constant = 6.626 x 10^{34}J-Sec)a. 2.26 eV

b. 1.98 eV

c. 1.17 eV

d. 0.74 eV

**Solutoin :**https://www.youtube.com/watch?v=ece35Kq_7jI

11. When the gate to source voltage (V

_{GS}) of a MOSFET with threshold voltage of 400 mV. The drain current observed is 1 mA. Neglecting the channel length modulation effect, and assuming that the MOSFET is operating at saturation, the drain current for an applied V_{GS}of 1400 mV isa. 0.5 mA

b. 2.0 mA

c. 3.5 mA

d. 4.0 mA

**Solutoin :**https://www.youtube.com/watch?v=jvXncirhK9c

12. If P is passivation, Q is n-well implant, R is metallization and S is source/drain diffusion, then the order in which they are carried out in a standard n-well CMOS fabrication process is

a. P-Q-R-S

b. Q-S-R-P

c. R-P-S-Q

d. S-R-Q-P

**Solutoin :**https://www.youtube.com/watch?v=dS__KGppUig

13. The action of a JFET in its equivalent circuit can best be represented as a

a. Current controlled current source

b. Current controlled voltage source

c. Voltage controlled current source

d. Voltage controlled voltage source

**Solutoin :**https://www.youtube.com/watch?v=gF67tPBH9M8