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MCQOPTIONS
This section includes 1017 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
An emitter-follower amplifier has an input impedance of 107 kΩ. The input signal is 12 mV. The approximate output voltage is (common-collector) |
| A. | 8.92 v |
| B. | 112 mv |
| C. | 12 mv |
| D. | 8.9 mv |
| Answer» D. 8.9 mv | |
| 102. |
Calculate the ripples of the filter output if a dc and ac voltmeter is used and measures the output signal from a filter circuit of 25 VDC and 1.5 Vrms |
| A. | 5% |
| B. | 10% |
| C. | 50% |
| D. | 6% |
| Answer» E. | |
| 103. |
At zero signal condition, a transistor sees load. |
| A. | dc |
| B. | ac |
| C. | both dc and ac |
| D. | resistive |
| Answer» B. ac | |
| 104. |
Maximum power output is obtained from a network when the load resistance is equal to the output resistance of the network as seen from the terminals of the load". The above statement is associated with |
| A. | mill man’s theorem |
| B. | thevenin\s theorem |
| C. | superposition theorem |
| D. | maximum power transfer theorem |
| Answer» E. | |
| 105. |
Consider a zener diode with a slope resistance of 10 Ω in series with a 90 Ω resistor fed from a dc supply containing a ripple voltage of 20mV peak-to-peak. Compute for the ripple voltage in load |
| A. | 1 mv p-p |
| B. | 2 mv p-p |
| C. | 1 v p-p |
| D. | 6mv p-p |
| Answer» C. 1 v p-p | |
| 106. |
When a FET with a lower transconductance is substituted into a FET amplifier circuit, what happens? |
| A. | the current gain does not change |
| B. | the voltage gain decreases |
| C. | the circuit disamplifies |
| D. | the input resistance decreases |
| Answer» C. the circuit disamplifies | |
| 107. |
A non-linear network does not satisfy |
| A. | superposition condition |
| B. | homogeneity condition |
| C. | both homogeneity as well as superposition condition |
| D. | homogeneity, superposition and associative condition |
| Answer» D. homogeneity, superposition and associative condition | |
| 108. |
The input impedance of the base of an emitter follower is usually |
| A. | low |
| B. | high |
| C. | shorted to ground |
| D. | open |
| Answer» C. shorted to ground | |
| 109. |
Which of the following digital IC logic families is most susceptible to static discharge? |
| A. | rtl |
| B. | ecl |
| C. | mos |
| D. | ttl |
| Answer» D. ttl | |
| 110. |
A class A amplifier with RC = 3.3 kΩ and RE = 1.2 kΩ has a VCC = 20 V. Find IC(sat). |
| A. | 4.4 ma |
| B. | 6.1 ma |
| C. | 16.7 ma |
| D. | 20 ma |
| Answer» B. 6.1 ma | |
| 111. |
You have an application for a power amplifier to operate on FM radio frequencies. The most likely choice would be a amplifier. |
| A. | class a |
| B. | class b |
| C. | class c |
| D. | class ab |
| Answer» D. class ab | |
| 112. |
Crossover distortion occurs in amplifiers. |
| A. | push-pull |
| B. | class a |
| C. | class b |
| D. | class ab |
| Answer» B. class a | |
| 113. |
The abbreviated designation for input current with a LOW input is |
| A. | vih. |
| B. | iih. |
| C. | iil. |
| D. | iol. |
| Answer» D. iol. | |
| 114. |
The frequency response of the combined amplifier can be compared with |
| A. | an or gate |
| B. | a negative feedback amplifier |
| C. | a positive filter |
| D. | an and gate |
| Answer» E. | |
| 115. |
Mill man’s theorem yields |
| A. | equivalent resistance |
| B. | equivalent impedance |
| C. | equivalent voltage source |
| D. | equivalent voltage or current source |
| Answer» E. | |
| 116. |
A transistor has how many pn junctions? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 117. |
Which of the following is not a common logic family used today? |
| A. | rtl |
| B. | ecl |
| C. | ttl |
| D. | cmos |
| Answer» B. ecl | |
| 118. |
The slope of the ac load line in the class A transformer-coupled transistor is . |
| A. | –1/rl (load resistor) |
| B. | 1/(a2rl) |
| C. | –1/(a2rl) |
| D. | 1/rl |
| Answer» D. 1/rl | |
| 119. |
One of the advantages of a Darlington pair is that it has enormous transformation capacity. |
| A. | voltage |
| B. | current |
| C. | impedance |
| D. | power |
| Answer» D. power | |
| 120. |
The driver stage usually employs amplifier. |
| A. | class a power |
| B. | class c |
| C. | push-pull |
| D. | class ab |
| Answer» B. class c | |
| 121. |
Find the voltage drop developed across a D’ Arsonval meter movement having an internal resistance of 1 kΩ and a full deflection current of 150uA. |
| A. | 150 µv |
| B. | 150 mv |
| C. | 150 v |
| D. | 200 mv |
| Answer» C. 150 v | |
| 122. |
The minimum input voltage recognized as a HIGH by a TTL gate is |
| A. | 0.8 v. |
| B. | 2.4 v. |
| C. | 2.0 v. |
| D. | 5.0 v |
| Answer» D. 5.0 v | |
| 123. |
The output stage of a multistage amplifier is also called |
| A. | mixer stage |
| B. | power stage |
| C. | detector stage |
| D. | f stage |
| Answer» C. detector stage | |
| 124. |
Which of the following is not a solution to interface problems between CMOS and TTL? |
| A. | pull-up resistor |
| B. | pull-down resistor |
| C. | level-shifter |
| D. | buffer |
| Answer» C. level-shifter | |
| 125. |
"In any linear bilateral network, if a source of e.m.f. E in any branch produces a current I in any other branch, then same e.m.f. acting in the second branch would produce the same current / in the first branch". The above statement is associated with |
| A. | compensation theorem |
| B. | superposition theorem |
| C. | reciprocity theorem |
| D. | none of the above |
| Answer» D. none of the above | |
| 126. |
Calculate the efficiency of a class B amplifier for a supply voltage of VCC = 20 V with peak output voltage of VL(p) = 18 V. Assume RL = 16 Ω. |
| A. | 78.54% |
| B. | 75% |
| C. | 70.69% |
| D. | 50% |
| Answer» D. 50% | |
| 127. |
In class A operation, the operating point is generally located of the d.c. load line. |
| A. | at cut off point |
| B. | at the middle |
| C. | at saturation point |
| D. | none of the above |
| Answer» C. at saturation point | |
| 128. |
When a transistor is fully switched ON, it is said to be |
| A. | shorted |
| B. | saturated |
| C. | open |
| D. | cut-off |
| Answer» C. open | |
| 129. |
Hybrid means |
| A. | mixed |
| B. | single |
| C. | biunique |
| D. | none of the above |
| Answer» B. single | |
| 130. |
The main use of a class C amplifier is |
| A. | as an rf amplifier |
| B. | as stereo amplifier |
| C. | in communication sound equipment |
| D. | as distortion generator |
| Answer» B. as stereo amplifier | |
| 131. |
Transformer coupling is an example of |
| A. | direct coupling |
| B. | ac coupling |
| C. | dc coupling |
| D. | impedance coupling |
| Answer» C. dc coupling | |
| 132. |
The has a physical channel between the drain and source. |
| A. | d-mosfet |
| B. | e-mosfet |
| C. | v-mosfet |
| D. | none of the above |
| Answer» B. e-mosfet | |
| 133. |
The current in any branch of a transistor amplifier that is operating is |
| A. | ac only |
| B. | the sum of ac and dc |
| C. | the difference of ac and dc |
| D. | dc only |
| Answer» C. the difference of ac and dc | |
| 134. |
The amount of power dissipated by the transistor is the of that drawn from the dc supply (set by the bias point) and the amount delivered to the ac load. |
| A. | product |
| B. | difference |
| C. | average |
| Answer» C. average | |
| 135. |
The push-pull circuit must use operation. |
| A. | class a |
| B. | class b |
| C. | class c |
| D. | class ab |
| Answer» C. class c | |
| 136. |
A complementary-symmetry amplifier has |
| A. | one pnp and one npn transistor |
| B. | two pnp transistors |
| C. | two npn transistors |
| D. | two pnp and two npn transistors |
| Answer» B. two pnp transistors | |
| 137. |
In practice, the efficiency of a capacitively coupled class A amplifier is about %. |
| A. | 25 |
| B. | 40 |
| C. | 70 |
| D. | 10 |
| Answer» E. | |
| 138. |
An open-collector TTL gate |
| A. | can sink current but cannot source current. |
| B. | can source current but cannot sink current. |
| C. | cannot source or sink current. |
| D. | can sink more current than a standard ttl gate. |
| Answer» B. can source current but cannot sink current. | |
| 139. |
Which of the following is a concern when using CMOS type devices? |
| A. | mechanical shock |
| B. | electrostatic discharge |
| C. | fan out |
| D. | under voltage |
| Answer» C. fan out | |
| 140. |
The ac variations at the output side of power supply circuits are called . |
| A. | ripples |
| B. | pulses |
| C. | waves |
| D. | filters |
| Answer» B. pulses | |
| 141. |
A silicon power transistor is operated with a heat sink (θSA = 1.5ºC/W). The transistor, rated at 150 W (25ºC), has θJC = 0.5º C/W, and the mounting insulation has θCS = 0.6 ºC/W. What is the maximum power that can be dissipated if the ambient temperature is 50ºC and TJmax = 200 ºC? |
| A. | 61.5 w |
| B. | 60.0 w |
| C. | 57.7 w |
| D. | 55.5 w |
| Answer» D. 55.5 w | |
| 142. |
What is the ideal maximum voltage gain of a common collector amplifier? |
| A. | unity |
| B. | infinite |
| C. | indeterminate |
| D. | zero |
| Answer» B. infinite | |
| 143. |
The has the hottest temperature in a power transistor. |
| A. | heat sink |
| B. | case |
| C. | junction |
| D. | none of the above |
| Answer» D. none of the above | |
| 144. |
Each input on a TTL gate is connected to the transistor's |
| A. | base |
| B. | collector |
| C. | gate |
| D. | emitter |
| Answer» E. | |
| 145. |
The output voltage of an emitter follower is across the |
| A. | emitter diode |
| B. | dc collector resistor |
| C. | load resistor |
| D. | emitter diode and external ac emitter resistance |
| Answer» D. emitter diode and external ac emitter resistance | |
| 146. |
The emitter of a transistor is generally doped the heaviest because it |
| A. | has to dissipate maximum power |
| B. | has to supply the charge carriers |
| C. | is the first region of the transistor |
| D. | must possess low resistance |
| Answer» B. has to supply the charge carriers | |
| 147. |
Fan-out for a typical TTL gate is . |
| A. | 10 |
| B. | 4 |
| C. | 54 |
| D. | 100 |
| Answer» B. 4 | |
| 148. |
Midpoint bias for a D-MOSFET is ID = , obtained by setting VGS = 0. |
| A. | idss / 2 |
| B. | idss / 3.4 |
| C. | idss |
| Answer» D. | |
| 149. |
Which of the following elements are important in determining the gain of the system in the high-frequency region? |
| A. | interelectrode capacitances |
| B. | wiring capacitances |
| C. | miller effect capacitance |
| D. | all of the above |
| Answer» E. | |
| 150. |
In class B operation, the current drawn from a single power supply has the form of rectified signal. |
| A. | a full-wave |
| B. | a half-wave |
| C. | both a full-wave and a half-wave |
| D. | none of the above |
| Answer» B. a half-wave | |