MCQ in Electronic Circuits Part 3 | ECE Board Exam

This is the Multiple Choice Questions in Electronic Circuits (Electronic Devices and Circuits, Electronic Circuit Analysis and Design) Part 3 of the Series as one of the Electronics Engineering Examination topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering field, Electronics Books, Journals and other Electronics References.

MCQ Topic Outline included in ECE Board Exam Syllabi

4. Electronic Devices and Circuits

• MCQ in Diode Wave Shaping Circuits and Special Diode Applications
• MCQ in BJT and FET Small Signal Analysis
• MCQ in Diode Equivalent Circuits
• MCQ in Voltage Multipliers, Power Supply, and Voltage Regulation
• MCQ in Bipolar Junction Transistor and FET

5. Electronic Circuit Analysis and Design

• MCQ in BJT and FET Frequency Response
• MCQ in Cascade and Cascode Connections
• MCQ in Current Mirrors and Current Source
• MCQ in Differential and Operational Amplifier
• MCQ in Feedback Systems, Oscillators, and Filters

Continue Practice Exam Test Questions Part 3 of the Series

⇐ MCQ in Electronic Circuits Part 2 | ECE Board Exam

Choose the letter of the best answer in each questions.

101. The three amplifiers are connected in a multistage arrangement each with a voltage gain of 30 dB. Compute for the overall voltage gain.

A. 90

B. 27,000

C. 10

D. 30

102. If Av is 50 Ai is 200, what is the power gain of a common emitter amplifier?

A. 1,000

B. 10,000

C. 100

D. 100,000

103. The gain of an amplifier with feedback is known as __________ gain.

A. Closed loop

B. Resonant

C. Open loop

D. Unity

104. Negative feedback is employed in

A. Oscillators

B. Rectifiers

C. Amplifiers

D. Receivers

105. The gain of an amplifier is expressed in dB unit because

A. It is a simple unit

B. Calculations become easy

C. Human ear response is logarithmic

D. It is the most appropriate unit

106. What is the typical value of the emitter bypass capacitor CE in a multistage amplifier?

A. About 0.1 µF

B. About 50 µF

C. About 100 pF

D. About 0.01 µF

107. In a multistage amplifier, if the stages have R and C component only, ___________ operation is apparent.

A. Class B

B. Class C

C. Class A

D. Class AB

108. In practice, what is normally varied in order to change the frequency of oscillation?

A. Capacitance

B. Inductance

C. Resistance

D. Impedance

109. What is the main consideration in the output stage of an amplifier?

A. Power output

B. Voltage gain

C. Power gain

D. Current gain

110. Transformer coupling provides high gain because

A. Transformer is very efficient

B. Impedance matching can be achieved

C. Transformer steps up the voltage

D. Transformer steps up the current

111. When negative voltage feedback is applied to an amplifier, its output impedance

A. Remains unchanged

B. Decreases

C. Increases

D. Becomes zero

112. An LC oscillator cannot be used to produce ____________ frequencies.

A. High

B. Very high

C. Audio

D. Very low

113. A transistor converts

A. Dc power into ac power

B. Ac power into dc power

C. High resistance into low resistance

D. Low resistance into high resistance

114. Hartley oscillator is commonly used in which of the following?

A. Radio receivers

B. TV receivers

C. Radio transmitters

D. CATV

115. An oscillator oscillates due to

A. Negative feedback

B. Positive feedback

C. Both positive and negative feedback

D. Neither positive nor negative feedback

116. Generally tuned amplifiers are operated in

A. Class C

B. Class A

C. Class B

D. Class AB

117. A tuned amplifier is used in what application?

A. Radio frequency

B. Audio frequency

C. Intermediate frequency

D. Low frequency

118. What is the ratio of output to input impedance of a CE amplifier?

A. Very low

B. Very high

C. Moderate

D. Approximately 1

119. For a constant output frequency, the simplest sinusoidal oscillator is the ___________.

A. Crystal oscillator

B. Phase-shift circuit

C. Colpitts circuits

D. Hartley circuit

120. The frequency stability of the oscillator output is maximum in ____________ oscillator.

A. LC

B. Crystal

C. Phase-shift

D. Wien bridge

121. Transformer coupling introduces what type of distortion?

A. Amplitude

B. Frequency

C. Phase

D. Intermodulation

122. A pulsating dc applied to power amplifiers causes

A. Burning of transistor

B. Hum in the circuit

C. Excessive forward voltage

D. Excessive reverse voltage

123. What is the disadvantage of impedance matching?

A. It gives distorted output

B. It requires a transformer

C. It gives low power output

D. It is expensive

124. In a phase-shift oscillator, ____________ RC sections are generally used.

A. Three

B. Four

C. Two

D. Five

125. In phase-shift oscillator, what are the frequency determining elements?

A. L and C

B. R, L and C

C. R and C

D. R and L

126. When the gain is 20 without feedback and 12 with negative feedback, feedback factor is

A. 0.033

B. 3/5

C. 5/3

D. 1/5

127. The input impedance of which amplifier depends strongly on load resistance?

A. CE

B. CC

C. CB

D. CD

128. What capacitors are used in transistor amplifiers?

A. Paper

B. Electrolytic

C. Mica

D. Mylar

129. An important limitation of crystal oscillator is

A. Its low output

B. Its high Q

C. Less availability of quartz crystal

D. Its high output

130. What type of feedback is used in Wien bridge oscillator?

A. Positive

B. Negative

C. Both positive and negative

D. Either positive or negative

131. Which of the items below is not a description of the two-stage amplifier?

A. The input resistance is equal to the input resistance of the first stage unless feedback is applied

B. Its output resistance is equal to the output resistance of the final stage unless feedback is applied

C. Its noise level is equal to the accumulated noise of the two stages, either by multiplying the noise voltage amplitudes together or by adding the noise decibel levels together

D. The output resistance is equal to the output resistance of the first stage unless feedback is applied.

132. What is the most costly coupling?

A. RC coupling

B. Direct

C. Transformer

D. Inductive

133. When the output of an amplifier is 10 V and 100 mV from the output is fed back to the input, feedback factor is

A. 10

B. 0.1

C. 0.01

D. 0.15

134. What is the piezoelectric effect in a crystal?

A. Voltage is developed because of mechanical stress

B. Change in resistance because of temperature

C. Change of frequency because of temperature

D. Current is developed due to force applied

135. The input resistance of a common emitter amplifier is affected by

A. Re, re and β

B. Rc and re

C. β and re

D. α and re

136. What is the typical Q of a crystal?

A. 100

B. 50

C. 1000

D. More than 10,000

137. What is the axis that connects the corners of a crystal?

A. X

B. Mechanical

C. Y

D. Z

138. Determine the attenuation in dB for a T-pad for which R1 = R2 = 40 Ω and R3 = 36 Ω. The pad connects a 50 Ω generator to a 50 Ω load.

A. 9.83 dB

B. 83.93 dB

C. 10.83 dB

D. 11.93 dB

139. What is usually employed at the output stage of an amplifier?

A. Class A power amplifier

B. Push-pull amplifier

C. Pre-amplifier

D. Differential amplifier

140. Why is it that the size of a power transistor is made considerably large?

A. To provide easy handling

B. To dissipate more heat

C. To simply construction

D. To facilitate connections

141. When crystal frequency increases with temperature, it has ______________ temperature co- efficient.

A. Positive

B. Negative

C. Zero

D. Infinite

142. What is the purpose of the bypass capacitor in a common-emitter amplifier?

A. It increases voltage gain

B. It decreases voltage gain

C. It provides ac grounding

D. No effect in the circuit

143. An emitter follower is equivalent to

A. Common emitter amplifier

B. Common collector amplifier

C. Common base amplifier

D. Hybrid connection

144. The crystal oscillator frequency is very stable due to ___________ of the crystal.

A. Rigidity

B. Ductility

C. High Q

D. Low Q

145. The bandwidth of an amplifier _____________ when negative feedback is applied.

A. Decreases

B. Remains unchanged

C. Becomes infinite

D. Increases

146. The term 1+ A β in the expression for gain with negative feedback is known as

A. Gain factor

B. Sacrifice factor

C. Feedback factor

D. Quality factor

147. Emitter follower employs ____________ negative feedback.

A. 50%

B. 25%

C. 75%

D. 100%

148. What application where one would most likely find a crystal oscillator?

A. Radio transmitter

B. AF generator

C. Radio receiver

D. Oscilloscope

149. What is the most important consideration in power amplifiers?

A. Collector efficiency

B. Biasing the circuit

C. To keep the transformer cool

D. Amplifier distortion

150. When the gain versus frequency curve of a transistor amplifier is not flat, __________ distortion is present.

A. Amplitude

B. Frequency

C. Intermodulation

D. Phase

Questions and Answers in Electronic Circuits

Following is the list of practice exam test questions in this brand new series:

Complete List of MCQ in Electronics Engineering per topic