Explore topic-wise MCQs in Electronics.

This section includes 303 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.

101.

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
102.

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
103.

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
104.

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
105.

Which of the following devices has the highest input impedance?

A. JFET
B. MOSFET
C. Crystal diode
D. ordinary transistor
Answer» C. Crystal diode
106.

___________ has the lowest noise-level

A. triode
B. ordinary trnsistor
C. tetrode
D. JFET
Answer» E.
107.

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
108.

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
109.

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
110.

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
111.

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
112.

A MOSFET has ___________ terminals

A. two
B. five
C. four
D. three
Answer» E.
113.

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
114.

A JFET is also called ___________ transistor

A. unipolar
B. bipolar
C. unijunction
D. none of the above
Answer» B. bipolar
115.

A JFET has ___________ power gain

A. small
B. very high
C. very small
D. none of the above
Answer» C. very small
116.

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
117.

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.
118.

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
119.

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.
120.

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.
121.

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
122.

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
123.

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
124.

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
125.

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
126.

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.
127.

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
128.

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
129.

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
130.

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
131.

A transistor has ___________

A. one pn junction
B. two pn junctions
C. three pn junctions
D. four pn junctions
Answer» C. three pn junctions
132.

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
133.

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
134.

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
135.

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
136.

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
137.

The input control parameter of a JFET is ___________

A. gate voltage
B. source voltage
C. drain voltage
D. gate current
Answer» B. source voltage
138.

A tuned amplifier uses ___________ load

A. Resistive
B. Capacitive
C. LC tank
D. Inductive
Answer» D. Inductive
139.

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
140.

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
141.

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
142.

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
143.

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
144.

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
145.

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
146.

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

A. Capacitive
B. Zero
C. Inductive
D. None of the above
Answer» C. Inductive
147.

At parallel resonance, the line current is ___________

A. Minimum
B. Maximum
C. Quite large
D. None of the above
Answer» B. Maximum
148.

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
149.

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
150.

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