Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the typical value for the input impedance Zi for JFETs?

A. 100 k
B. 1 M
C. 10 M
D. 1000 M
Answer» E.
Discussion
2.

For what value of ID is gm equal to 0.5 gm0?

A. 0 mA
B. 0.25 IDSS
C. 0.5 IDSS
D. IDSS
Answer» C. 0.5 IDSS
Discussion
3.

What is the range of gm for JFETs?

A. 1 S to 10 S
B. 100 S to 1000 S
C. 1000 S to 5000 S
D. 10000 S to 100000 S
Answer» D. 10000 S to 100000 S
Discussion
4.

An FET is a ________-controlled device.

A. current
B. voltage
Answer» C.
Discussion
5.

A BJT is a ________-controlled device.

A. current
B. voltage
Answer» B. voltage
Discussion
6.

Digital MOSFET switches are used in the sample-and-hold circuit of an analog-to-digital converter.

A. True
B. False
Answer» C.
Discussion
7.

In an analog MOSFET switch, the input is applied to the gate and the output is taken from the source.

A. True
B. False
Answer» C.
Discussion
8.

In a class D amplifier, the low-pass filter comes directly after the pulse-width modulator.

A. True
B. False
Answer» C.
Discussion
9.

Class D amplifier efficiencies can reach practical levels of more than 90%.

A. True
B. False
Answer» B. False
Discussion
10.

In a class D amplifier, the output transistors are operated in a nonlinear mode.

A. True
B. False
Answer» B. False
Discussion
11.

The common-drain configuration has extremely high input resistance.

A. True
B. False
Answer» B. False
Discussion
12.

The common-source configuration has extremely high input resistance.

A. True
B. False
Answer» B. False
Discussion
13.

The common-gate configuration has extremely high input resistance.

A. True
B. False
Answer» C.
Discussion
14.

The common-drain amplifier is also called a source-follower.

A. True
B. False
Answer» B. False
Discussion
15.

Generally, higher voltage gains can be achieved with bipolar amplifiers than with FET amplifiers.

A. True
B. False
Answer» B. False
Discussion
16.

Bypassing a source resistor reduces the voltage gain.

A. True
B. False
Answer» C.
Discussion
17.

A load resistance connected to the output of an amplifier reduces the voltage gain.

A. True
B. False
Answer» B. False
Discussion
18.

There is a 180º phase inversion between the gate and source voltages.

A. True
B. False
Answer» C.
Discussion
19.

There is no phase inversion between the gate and the drain voltages.

A. True
B. False
Answer» C.
Discussion
20.

The voltage gain of a common-source amplifier is found by the product of gm and Rd.

A. True
B. False
Answer» B. False
Discussion
21.

What is the input resistance (Rin(source)) of a common-gate amplifier?

A. Rs
B. [B].
C. 1 / gm
D. none of the above
Answer» D. none of the above
Discussion
22.

There is a ________º phase inversion between gate and source in a source follower.

A. 0
B. 90
C. 180
D. none of the above
Answer» B. 90
Discussion
23.

Refer to this figure. If R6 opened, the signal at the drain of Q1 would

A. increase.
B. decrease.
C. remain the same.
D. distort.
Answer» D. distort.
Discussion
24.

Refer to this Figure. If Vin was increased in amplitude a little, the signal voltage at the source of Q2 would

A. increase.
B. decrease.
C. remain the same.
D. distort.
Answer» D. distort.
Discussion
25.

Refer to this figure. If C2 shorted, Vout would

A. increase.
B. decrease.
C. remain the same.
D. distort.
Answer» E.
Discussion
26.

Refer to this figure. If R7 were to decrease in value, Vout would

A. increase.
B. decrease.
C. remain the same.
D. distort.
Answer» C. remain the same.
Discussion
27.

Refer to this figure. If ID = 4 mA, IDSS = 16 mA, and VGS(off) = –8 V, find VDS.

A. 19.2 V
B. –6 V
C. 10.8 V
D. 30 V
Answer» D. 30 V
Discussion
28.

Refer to this figure. If C4 opened, the signal voltage at the drain of Q1 would

A. increase.
B. decrease.
C. remain the same.
D. distort.
Answer» D. distort.
Discussion
29.

Refer to this figure. The approximate value of Rin is

A. 100 M.
B. 1.5 k.
C. 3.3 k.
D. 48 M.
Answer» B. 1.5 k.
Discussion
30.

Refer to this figure. If gm = 4000 mS and a signal of 75 mV rms is applied to the gate, calculate the p-p output voltage.

A. 990 mV
B. 1.13 V p-p
C. 2.8 V p-p
D. 990 V p-p
Answer» D. 990 V p-p
Discussion
31.

Refer to this figure. If ID = 4 mA, find the value of VGS.

A. 10.8 V
B. 6 V
C. –0.7 V
D. –6 V
Answer» E.
Discussion
32.

Refer to this figure. If Vin = 1 V p-p, the output voltage Vout would be

A. undistorted.
B. clipped on the negative peaks.
C. clipped on the positive peaks.
D. 0 V p-p.
Answer» B. clipped on the negative peaks.
Discussion
33.

Refer to this figure. If Vin = 20 mV p-p what is the output voltage?

A. 176 mV p-p
B. 88 mV p-p
C. 48 mV p-p
D. 24 mV p-p
Answer» B. 88 mV p-p
Discussion
34.

Refer to this figure. Find the value of VD.

A. 20 V
B. 11 V
C. 10 V
D. 9 V
Answer» E.
Discussion
35.

Refer to this figure. The voltage gain is

A. 1.2.
B. 2.4.
C. 4.4.
D. 8.8.
Answer» E.
Discussion
36.

Refer to this figure. If VGS = –6 V, calculate the value of RS that will provide this value.

A. 2.2 k
B. 1.2 k
C. 600 k
D. 100 k
Answer» C. 600 k
Discussion
37.

Refer to this figure. For midpoint biasing, ID would be

A. 10 mA.
B. 7.5 mA.
C. 5 mA.
D. 2.5 mA.
Answer» D. 2.5 mA.
Discussion
38.

A JFET cascade amplifier employs

A. 2 common-gate amplifiers.
B. 2 common-source amplifiers.
C. 1 common-gate and 1 common-source amplifier.
D. 1 common-gate and 1 common-drain amplifier.
Answer» D. 1 common-gate and 1 common-drain amplifier.
Discussion
39.

If I D = I DSS / 2, g m = ________ g mo .

A. 1
B. 0.707
C. 0.5
D. -
Answer» C. 0.5
Discussion
40.

In a common-source amplifier, the purpose of the bypass capacitor, C 2 , is to

A. keep the source effectively at ac ground.
B. provide a dc path to ground.
C. provide coupling to the input.
D. provide coupling to the load.
Answer» B. provide a dc path to ground.
Discussion
41.

Referring to this figure, calculate Z o if y os = 40 S.

A. 2.92 k
B. 3.20 k
C. 3.25 k
D. 3.75 k
Answer» B. 3.20 k
Discussion
42.

Referring to this figure, calculate A v if y os = 20 S.

A. –3.48
B. –3.56
C. –3.62
D. –4.02
Answer» D. –4.02
Discussion
43.

The E-MOSFET is quite popular in ________ applications.

A. digital circuitry
B. high-frequency
C. buffering
D. All of the above
Answer» E.
Discussion
44.

What limits the signal amplitude in an analog MOSFET switch?

A. the switch input capacitance
B. V GS(th)
C. the switch's power handling
D. V DS
Answer» C. the switch's power handling
Discussion
45.

Referring to the transfer characteristics shown below, calculate g m at V GSQ = –1 V.

A. 2 mS
B. 3 mS
C. 4 mS
D. 5 mS
Answer» C. 4 mS
Discussion
46.

For an FET small-signal amplifier, one could go about troubleshooting a circuit by ________.

A. viewing the circuit board for poor solder joints
B. using a dc meter
C. applying a test ac signal
D. All of the above
Answer» E.
Discussion
47.

E-MOSFETs are generally used in switching applications because

A. of their very low input capacitance.
B. of their threshold characteristic (V GS(th) ).
C. of their high-frequency response capabilities.
D. of their power handling.
Answer» C. of their high-frequency response capabilities.
Discussion
48.

Input resistance of a common-drain amplifier is

A. R G || R IN(gate) .
B. R G + R IN(gate) .
C. R G .
D. R IN(gate) .
Answer» B. R G + R IN(gate) .
Discussion
49.

Calculate g m and r d if y fs = 4 mS and y os = 15 S.

A. 4 mS, 66.7 k
B. 4 mS, 15 k
C. 66.7 k , 4 mS
D. None of the above
Answer» B. 4 mS, 15 k
Discussion
50.

What is the range of g m for JFETs?

A. 1 S to 10 S
B. 100 S to 1000 S
C. 1000 S to 5000 S
D. 10000 S to 100000 S
Answer» D. 10000 S to 100000 S
Discussion