1. Which of the following are true for h-parameters of transistors 1. They are real numbers at audio frequencies. 2 They are easy to measure. 3. They vary widely with temperature. Select the correct answer using the codes given below ?

1 and 3 only

2 and 3 only

1,2 and 3

1 and 2 only

Answer: 1,2 and 3

Explanation:


2. N-channel FETs are superior to P-channel FETs because they have ?

mobility of electrons in N-channel is greater than mobility of holes in P-channel

higher input impedance

lower pinch-off voltage

lower switching time

Answer: mobility of electrons in N-channel is greater than mobility of holes in P-channel

Explanation:


3. Thermal runaway is not encountered in FETs because ?

the mobility of the carriers increases with increase in temperature

IDS has a zero temperature coefficient

IDS has a negative temperature coefficient

IDS has a positive temperature coefficient

Answer: IDS has a zero temperature coefficient

Explanation:


4. How is an N-channel junction field effect transistor operated as an amplifier ?

With a shorted gate-source junction

With an open gate-source junction

With a forward bias gate-source junction

With a reverse bias gate-source junction

Answer: With a reverse bias gate-source junction

Explanation:


5. What is the correct sequence of the following steps in the fabrication of a monolithic, bipolar junction transistor? 1. Emitter diffusion 2. Base diffusion 3. Buried layer formation 4. Epi-layer formation. Select the correct answer using the codes given below: Codes: ?

3, 4, 2, 1

4,3,2,1

4,3,1,2

3,4, 1, 2

Answer: 4,3,2,1

Explanation:


6. Diffusion of impurities in a semiconductor is carried out in a farmace through which a steady stream of impurity atoms is passed during the entire diffusion process. What would be the type of profile of the impurity stoms inside the semiconductor ?

Gaussian

Exponential

Linear

Complementary error function

Answer: Complementary error function

Explanation:


7. The p-type substrate in a conventional pn-junction isolated integrated circuit should be connected to ?

the most negative potential available in the circuit

the most positive potential available in the circuit

a dc ground potential

nowhere, i.e. left floating

Answer: the most negative potential available in the circuit

Explanation:


8. The p-type epitaxial layer grown over an n-type substrate for fabricating a bipolar transistor will function as ?

the collector contact for a p-n-p transistor

the emitter of a p-n-p transistor

the collector of p-n-p transistor

the base of an n-p-n transistor

Answer: the collector of p-n-p transistor

Explanation:


9. In fabricating silicon BJT in ICs by the epitaxial process, the number of diffusions used is usually ?

4

2

6

3

Answer: 2

Explanation:


10. The commercial temperature range of ICs is ?

-25°C to 85°C

0-100°C

-55°C to 125°C

0-70°C

Answer: 0-70°C

Explanation: