This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Small Signal Operations and Model”.

1. A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of R?p.

a) 625 ohm

b) 1250 ohm

c) 2500 ohm

d) 5000 ohm

2. A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of Re.

a) 2.5 ohm

b) 20.6 ohm

c) 25.2 ohm

d) 30.4 ohm

3. A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of gm.

a) 12mA/V

b) 24 mA/V

c) 36 mA/V

d) 48 mA/V

4. A transistor operating with nominal gm of 60 mA/V has a ß that ranges from 50 to 200. Also, the bias circuit, being less than ideal, allows a 20% variation in Ic. What is the smallest value found of the resistance looking into the base?

a) 347 ohm

b) 694 ohm

c) 1041 ohm

d) 1388 ohm

5. A designer wishes to create a BJT amplifier with a gm of 50 mA/V and a base input resistance of 2000 O or more. What is the minimum ß he can tolerate for the transistor used?

a) 100

b) 150

c) 200

d) 250

6. Which of the following is true?

a) Ib = ß Ic

b) Ib = ß + 1/ Ic

c) Ib = Ic/ß

d) Ib = Ic/ ß – 1

7. A transistor operating with nominal gm of 60 mA/V has a ß that ranges from 50 to 200. Also, the bias circuit, being less than ideal, allows a 20% variation in Ic. What is the largest value found of the resistance looking into the base?

a) 1050 ohm

b) 21000 ohm

c) 3150 ohm

d) 4200 ohm

8. A designer wishes to create a BJT amplifier with a gm of 50 mA/V and a base input resistance of 2000 O or more. What emitter bis current should he choose?

a) 1.06 mA

b) 1.16 mA

c) 1.26 mA

d) 1.36 mA

9. The SI units of transconductance is

a) Ampere/ volt

b) Volt/ ampere

c) Ohm

d) Siemens

10. Which of the following represents the correct mathematical form of the term denoted by the symbol Rp?

a) ß/gm

b) Vt/Ib

c) All of the mentioned

d) None of the mentioned