# MCQ in Electronic Circuits Part 3 | ECE Board Exam

(Last Updated On: May 4, 2019) This is the Multiples Choice Questions Part 3 of the Series in Electronic (Audio/RF) Circuit/Analysis/Design as one of the Electronics Engineering 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

• MCQ in Oscillators
• MCQs in Rectifier
• MCQs in Filters
• MCQs in Voltage Regulation

### Continue Practice Exam Test Questions Part 3 of the Series

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. Compute for the overall voltage gain.

A. 90

B. 27,000

C. 10

D. 30

Solution:

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

Solution:

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

A. Closed loop

B. Resonant

C. Open loop

D. Unity

Solution:

104. Negative feedback is employed in

A. Oscillators

B. Rectifiers

C. Amplifiers

Solution:

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

Solution:

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

Solution:

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

Solution:

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

A. Capacitance

B. Inductance

C. Resistance

D. Impedance

Solution:

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

Solution:

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

Solution:

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

A. Remains unchanged

B. Decreases

C. Increases

D. Becomes zero

Solution:

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

A. High

B. Very high

C. Audio

D. Very low

Solution:

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

Solution:

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

D. CATV

Solution:

115. An oscillator oscillates due to

A. Negative feedback

B. Positive feedback

C. Both positive and negative feedback

D. Neither positive nor negative feedback

Solution:

116. Generally tuned amplifiers are operated in

A. Class C

B. Class A

C. Class B

D. Class AB

Solution:

117. A tuned amplifier is used in what application?

B. Audio frequency

C. Intermediate frequency

D. Low frequency

Solution:

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

Solution:

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

Solution:

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

A. LC

B. Crystal

C. Phase-shift

D. Wien bridge

Solution:

121. Transformer coupling introduces what type of distortion?

A. Amplitude

B. Frequency

C. Phase

D. Intermodulation

Solution:

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

Solution:

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

Solution:

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

A. Three

B. Four

C. Two

D. Five

Solution:

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

Solution:

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

Solution:

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

A. CE

B. CC

C. CB

D. CD

Solution:

128. What capacitors are used in transistor amplifiers?

A. Paper

B. Electrolytic

C. Mica

D. Mylar

Solution:

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

Solution:

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

Solution:

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.

Solution:

132. What is the most costly coupling?

A. RC coupling

B. Direct

C. Transformer

D. Inductive

Solution:

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

A. 10

B. 0.1

C. 0.01

D. 0.15

Solution:

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

Solution:

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

Solution:

136. What is the typical Q of a crystal?

A. 100

B. 50

C. 1000

D. More than 10,000

Solution:

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

A. X

B. Mechanical

C. Y

D. Z

Solution:

138. Determine the attenuation in dB for a T-pad for which R1=R2=40Ω 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

Solution:

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

Solution:

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

Solution:

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

A. Positive

B. Negative

C. Zero

D. Infinite

Solution:

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

Solution:

143. An emitter follower is equivalent to

A. Common emitter amplifier

B. Common collector amplifier

C. Common base amplifier

D. Hybrid connection

Solution:

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

A. Rigidity

B. Ductility

C. High Q

D. Low Q

Solution:

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

A. Decreases

B. Remains unchanged

C. Becomes infinite

D. Increases

Solution:

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

Solution:

147. Emitter follower employs ____________ negative feedback.

A. 50%

B. 25%

C. 75%

D. 100%

Solution:

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

B. AF generator

D. Oscilloscope

Solution:

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

Solution:

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

Solution:

### Questions and Answers in Electronic Circuits

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

MCQ in Electronic Circuits
PART 1: MCQs from Number 1 – 50                        Answer key: PART 1
PART 2: MCQs from Number 51 – 100                   Answer key: PART 2
PART 3: MCQs from Number 101 – 150                 Answer key: PART 3
PART 4: MCQs from Number 151 – 200                 Answer key: PART 4
PART 5: MCQs from Number 201 – 250                 Answer key: PART 5
PART 6: MCQs from Number 251 – 300                 Answer key: included
PART 7: MCQs from Number 301 – 350                 Answer key: included
PART 8: MCQs from Number 351 – 400                 Answer key: included
PART 9: MCQs from Number 401 – 415                 Answer key: included

### Complete List of MCQ in Electronics Engineering per topic

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