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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. | 0° |
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. | 0° |
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 | |