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.

The two important advantages of a JFET are ___________

A. high input impedance and square-law property
B. inexpensive and high output impedance
C. low input impedance and high output impedance
D. none of the above
Answer» B. inexpensive and high output impedance
2.

The pinch-off voltage of a JFET is about ___________

A. 5 V
B. 0.6 V
C. 15 V
D. 25 V
Answer» B. 0.6 V
3.

In a p-channel JFET, the charge carriers are ___________

A. electrons
B. holes
C. both electrons and holes
D. none of the above
Answer» C. both electrons and holes
4.

The transconductance of a JFET ranges from ___________

A. 100 to 500 mA/V
B. 500 to 1000 mA/V
C. 0.5 to 30 mA/V
D. above 1000 mA/V
Answer» D. above 1000 mA/V
5.

Which of the following devices has the highest input impedance?

A. JFET
B. MOSFET
C. Crystal diode
D. ordinary transistor
Answer» C. Crystal diode
6.

___________ has the lowest noise-level

A. triode
B. ordinary trnsistor
C. tetrode
D. JFET
Answer» E.
7.

A n-channel D-MOSFET with a positive VGS is operating in ___________

A. the depletion-mode
B. the enhancement-mode
C. cut off
D. saturation
Answer» C. cut off
8.

When drain voltage equals the pinch-off-voltage, then drain current ___________ with the increase in drain voltage

A. decreases
B. increases
C. remains constant
D. none of the above
Answer» D. none of the above
9.

For VGS = 0 V, the drain current becomes constant when VDS exceeds

A. cut off
B. VDD
C. VP
D. o V
Answer» D. o V
10.

At cut-off, the JFET channel is ___________

A. at its widest point
B. completely closed by the depletion region
C. extremely narrow
D. reverse baised
Answer» C. extremely narrow
11.

The pinch-off voltage in a JFET is analogous to ___________ voltage in a vacuum tube

A. anode
B. cathode
C. grid cut off
D. none of the above
Answer» D. none of the above
12.

A MOSFET has ___________ terminals

A. two
B. five
C. four
D. three
Answer» E.
13.

A common base configuration of a pnp transistor is analogous to ___________ of a JFET

A. common source configuration
B. common drain configuration
C. common gate configuration
D. none of the above
Answer» D. none of the above
14.

A JFET is also called ___________ transistor

A. unipolar
B. bipolar
C. unijunction
D. none of the above
Answer» B. bipolar
15.

A JFET has ___________ power gain

A. small
B. very high
C. very small
D. none of the above
Answer» C. very small
16.

A JFET is a ___________ driven device

A. current
B. voltage
C. both current and voltage
D. none of the above
Answer» C. both current and voltage
17.

The Q of a tuned amplifier is 50. If the resonant frequency for the amplifier is 1000kHZ, then bandwidth is ___________

A. 10kHz
B. 40 kHz
C. 30 kHz
D. 20 kHz
Answer» E.
18.

The stabilisation of operating point in potential divider method is provided by ___________

A. RE consideration
B. RC consideration
C. VCC consideration
D. None of the above
Answer» B. RC consideration
19.

A class C amplifier always drives ___________ load

A. A pure resistive
B. A pure inductive
C. A pure capacitive
D. A resonant tank
Answer» E.
20.

In a particular biasing circuit, the value of RE is about

A. 10 kΩ
B. 1 MO
C. 100 kΩ
D. 800 O
Answer» E.
21.

Thermal runaway occurs when ___________

A. Collector is reverse biased
B. Transistor is not biased
C. Emitter is forward biased
D. Junction capacitance is high
Answer» C. Emitter is forward biased
22.

For proper operation of the transistor, its collector should have ___________

A. Proper forward bias
B. Proper reverse bias
C. Very small size
D. None of the above
Answer» C. Very small size
23.

The zero signal IC is generally ___________ mA in the initial stages of a transistor amplifier

A. 4
B. 1
C. 3
D. More than 10
Answer» C. 3
24.

In parallel resonance, there is ___________

A. Both voltage and current amplification
B. Voltage amplifications
C. Current amplification
D. None of the above
Answer» D. None of the above
25.

In series resonance, there is ___________

A. Voltage amplification
B. Current amplification
C. Both voltage and current amplification
D. None of the above
Answer» B. Current amplification
26.

In voltage divider bias, VCC = 25 V; R1 = 10 kΩ; R2 = 2.2 V ; RC = 3.6 V and RE =1 kΩ. What is the emitter voltage?

A. 7 V
B. 3 V
C. 5 V
D. 8 V
Answer» E.
27.

The voltage gain of a tuned amplifier is ___________ at resonant frequency

A. Minimum
B. Maximum
C. Half-way between maximum and minimum
D. Zero
Answer» C. Half-way between maximum and minimum
28.

The disadvantage of voltage divider bias is that it has ___________

A. High stability factor
B. Low base current
C. Many resistors
D. None of the above
Answer» D. None of the above
29.

If biasing is not done in an amplifier circuit, it results in ___________

A. Decrease in the base current
B. Unfaithful amplification
C. Excessive collector bias
D. None of the above
Answer» C. Excessive collector bias
30.

The collector-base junction in a transistor has ___________

A. forward bias at all times
B. reverse bias at all times
C. low resistance
D. none of the above
Answer» C. low resistance
31.

A transistor has ___________

A. one pn junction
B. two pn junctions
C. three pn junctions
D. four pn junctions
Answer» C. three pn junctions
32.

As the temperature of a transistor goes up, the base emitter resistance ___________

A. decreases
B. increases
C. remains the same
D. none of the above
Answer» B. increases
33.

The source terminal of a JEFT corresponds to ___________ of a vacuum tube

A. plate
B. cathode
C. grid
D. none of the above
Answer» C. grid
34.

A JFET has three terminals, namely ___________

A. cathode, anode, grid
B. emitter, base, collector
C. source, gate, drain
D. none of the above
Answer» D. none of the above
35.

A MOSFET uses the electric field of a ___________ to control the channel current

A. capacitor
B. battery
C. generator
D. none of the above
Answer» B. battery
36.

The input impedance of a JFET is ___________ that of an ordinary transistor

A. equal to
B. less than
C. more than
D. none of the above
Answer» D. none of the above
37.

The input control parameter of a JFET is ___________

A. gate voltage
B. source voltage
C. drain voltage
D. gate current
Answer» B. source voltage
38.

A tuned amplifier uses ___________ load

A. Resistive
B. Capacitive
C. LC tank
D. Inductive
Answer» D. Inductive
39.

For frequencies below the resonant frequency , a parallel LC circuit behaves as a ___________ load

A. Inductive
B. Resistive
C. Capacitive
D. None of the above
Answer» B. Resistive
40.

For frequencies above the resonant frequency , a series LC circuit behaves as a ___________ load

A. Resistive
B. Inductive
C. Capacitive
D. None of the above
Answer» C. Capacitive
41.

For frequencies below resonant frequency, a series LC circuit behaves as a ___________ load

A. Resistive
B. Capacitive
C. Inductive
D. None of the above
Answer» C. Inductive
42.

For frequencies above the resonant frequency, a parallel LC circuit behaves as a ___________ load

A. Capacitive
B. Resistive
C. Inductive
D. None of the above
Answer» B. Resistive
43.

At series or parallel resonance, the circuit behaves as a ___________ load

A. Capacitive
B. Resistive
C. Inductive
D. None of the above
Answer» C. Inductive
44.

At parallel resonance, the phase angle between the applied voltage and circuit current is ___________

A. 90°
B. 180°
C.
D. None of the above
Answer» D. None of the above
45.

At series resonance, the net reactive component of circuit current is ___________

A. Zero
B. Inductive
C. Capacitive
D. None of the above
Answer» B. Inductive
46.

At parallel resonance, the net reactive component circuit current is ___________

A. Capacitive
B. Zero
C. Inductive
D. None of the above
Answer» C. Inductive
47.

At parallel resonance, the line current is ___________

A. Minimum
B. Maximum
C. Quite large
D. None of the above
Answer» B. Maximum
48.

At series resonance, the phase angle between applied voltage and circuit is ___________

A. 90°
B. 180°
C.
D. None of the above
Answer» D. None of the above
49.

For faithful amplification by a transistor circuit, the value of VCE should ___________ for silicon transistor

A. Not fall below 1 V
B. Be zero
C. Be 0.2 V
D. None of the above
Answer» B. Be zero
50.

The point of intersection of d.c. and a.c. load lines represents ___________

A. Operating point
B. Current gain
C. Voltage gain
D. None of the above
Answer» B. Current gain