This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “The Junction Field-Effect Transistor – 2″.
1. Two identical FETs, each characterized by the parameters g_m and r_d are connected in parallel .The composite FET is then characterized by the parameters_____________
a) gm/2 and 2rd
b) gm/2 and 2rd
c) 2gm and rd/2
d) 2gm and rd/2
2. The pinch off voltage of JFET is 5v. What is its cut off voltage?
3. Which of the following can be considered to be an advantage of FET amplifier as compared to BJT amplifier?
A – Higher input impedance
B – Good bias stability
C – Higher gain-bandwidth product
D – Lower noise figure
Select the correct answer using the codes given below
a) A, B and C
b) A, B and D
c) B, C and D
d) A, C and D
4. The action of JFET in its equivalent circuit can be represented as which of the following?
a) Current controlled current source
b) Current controlled voltage source
c) Voltage controlled current source
d) Voltage controlled Voltage source
5. FET amplifier does not obey the law of conservation of energy.
6. At higher frequency, the capacitance of an amplifier circuit is mainly because of which capacitance?
a) Coupling capacitors
b) Stray capacitance
7. Which of the following is the main advantage of Self bias?
a) Eliminates the need of two power supply
b) Maximum stability
c) Minimum stability
d) Maximum & Minimum stability
8. Which of the following is the necessary condition to design an amplifier?
a) Vce ≤ 1⁄10 of RC
b) |Vce| ≤ 1⁄10 of RC
c) |Vce| ≤ 1⁄1000 of RC
d) |Vce| ≤ 1⁄100 of RC
9. Which of the following is the equation for stray capacitance frequency?
a) FH = 1/27R
b) FH = 1/R
c) FH = 54/27R
d) FH = 11/27R
10. What is the maximum value of gain of an amplifier?