# MCQ in Electronic Circuits Part 4 | ECE Board Exam

(Last Updated On: May 4, 2019) This is the Multiples Choice Questions Part 4 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 Amplifiers
• MCQ in Oscillators
• MCQ in Rectifier
• MCQ in Filters
• MCQ in Voltage Regulation

### Continue Practice Exam Test Questions Part 4 of the Series

Choose the letter of the best answer in each questions.

151. In a Colpitt’s oscillator, feedback is obtained

A. By magnetic induction

B. By a tickler coil

C. From the center of split capacitors

D. From the center of split inductors

Solution:

152. When the collector resistor in a common emitter amplifier is increased in value the voltage gain

A. Increases

B. Decreases

C. Remain the same

D. Becomes erratic

Solution:

153. The output signal of CE amplifier is always

A. Out of phase with the input signal

B. Equal to the input signal

C. In phase with the input signal

D. Larger than the input signal

Solution:

154. What is the purpose of capacitors in a transistor amplifier?

A. To protect the transistor

B. To cool the transistor

C. To couple or bypass ac component

D. To provide biasing

Solution:

155. What is the phase difference between voltage across collector load and signal voltage in a common emitter amplifier?

A. 0°

B. 270°

C. 180°

D. 90°

Solution:

156. When CE configuration is used for an oscillator, the voltage fed back must

A. Be inverted by 180°

B. Be taken from a capacitor

C. Have a 0° phase shift

D. Taken from an inductor

Solution:

157. Class B operation has a maximum possible frequency of ___________ percent.

A. 100%

B. 78.5%

C. 75%

D. 2.2%

Solution:

158. What is the most stable sine-wave oscillator which uses piezo-electric quartz crystal?

A. Crystal oscillator

B. Wien-bridge oscillator

C. DC restorer

D. Hartley and Colpitts oscillator

Solution:

159. To sustain oscillations, the power gain of the amplifier may be

A. Between 0.1 and 0.5

B. Any value form 0.5 upward

C. Equal to or greater than 1

D. Infinite

Solution:

160. In a phase shift oscillator, 180° phase-shift is obtained

A. A transformer

B. LC tank circuit

C. Three RC sections

D. Three LC sections

Solution:

161. Feedback circuit usually employs __________ network

A. Resistive

B. Inductive

C. Capacitive

D. Active

Solution:

162. Emitter follower is used for

A. Impedance matching

B. Voltage gain

C. Current gain

D. Power gain

Solution:

163. One of the items below is a characteristic of cascaded amplifiers?

A. Doubles transconductance

B. Total gain is lessen

C. Increased overall gain

D. Increased overall amplification ratio

Solution:

164. Logic analyzer is used to

A. Verify the logic operation of the gates in a circuit

B. To display the fall time

C. To sample and display systems signal

D. To analyze the logic operation of the system

Solution:

165. Quartz crystal is most commonly used in crystal oscillators because

A. It is easily available

B. It has superior electrical properties

C. It is quite inexpensive

D. It is very rugged

Solution:

166. The operating frequency of a Wien-bridge oscillator is given by

Solution:

167. Which operation gives the maximum distortion?

A. Class A

B. Class C

C. Class B

D. Class AB

Solution:

168. Low efficiency of a power amplifier results in

A. Low forward bias

B. Less battery consumption

C. More battery consumption

D. Low power output

Solution:

169. In an LC oscillator, the frequency of oscillations is given by

Solution:

170. Class A operation has a maximum possible efficiency of ___________ percent.

A. 100%

B. 50%

C. 75%

D. 25%

Solution:

171. Which of the following amplifier below is a choice when higher power gain is a requirement?

A. Common base

B. Common emitter

C. Common collector

D. Hybrid connection

Solution:

172. The signal generator generally used in laboratories is ____________ oscillator

A. Crystal

B. Wien-bridge

C. Hartley

D. Phase-shift

Solution:

173. A buffer amplifier is used for

Solution:

174. Parasitic oscillations are caused by

A. Output negative feedback

B. Push-pull operation

C. Poor interstage coupling

D. Transistor interelectrode capacitance

Solution:

175. Which is a fixed-frequency oscillator

A. Phase-shift oscillator

B. Colpitt’s oscillator

C. Hartley oscillator

D. Crystal oscillator

Solution:

176. The approximate operating frequency of a phase shift oscillator is given by

Solution:

177. The frequency of the ripple voltage at the output of a full-wave rectifier at 60 cycles.

A. 120 cycles

B. 60 cycles

C. 240 cycles

D. 480 cycles

Solution:

178. Cascaded amplifiers total decibel gain is equal to

A. The sum of the individual gains

B. The product of the individual gains

C. The difference of the individual gains

D. The quotient of the individual gains

Solution:

179. In an LC oscillator, if the value of L is increased four times, then the frequency of oscillation is

A. Decreased 2 times

B. Decreased 4 times

C. Increased 2 times

D. Increased 4 times

Solution:

180. A class A power amplifier is otherwise known as

A. Single ended amplifier

B. Darlington amplifier

C. Symmetrical amplifier

D. Differential amplifier

Solution:

181. The power input to a power amplifier is __________ quantity.

A. ac

B. Pulsating dc

C. dc

D. sinusoidal

Solution:

182. When shock-excited, a crystal will produce alternating emf longer than an LC circuit because

A. has greater mechanical strength

B. has fewer losses

C. is small-sized

D. is very rigid

Solution:

183. The stability of a regulated power supply is equivalent to

A. change of output voltage over the change in supply voltage

B. change in supply voltage over the change of output voltage

C. product of the output voltage and supply voltage

D. the difference of an output voltage to its supply voltage

Solution:

184. What oscillator circuit uses a tapped coil in the tuned circuit?

A. Hartley

B. Colpitts

C. Crystal

D. Pierce

Solution:

185. If you move towards an oscillating circuit, its frequency changes because of

A. Hand capacitance

B. Movement of the body

C. Noise of foot

D. Stray capacitance

Solution:

186. Which of the following is not a FET amplifier configuration?

A. Common base amplifier

B. Common drain amplifier

C. Common source amplifier

D. Common gate amplifier

Solution:

187. The number of transistor in a single stage amplifier is

A. Two

B. Three

C. One

D. Four

Solution:

188. Series current negative feedback occurs when the feedback voltage is proportional to the output

A. Voltage

B. Impedance

C. Current

D. Power

Solution:

189. Which of the following is NOT an oscillator requirement?

A. Attenuator

B. Amplifier

C. Tank circuit

D. Feedback

Solution:

190. An amplifier with efficiency of 85% is likely to be

A. Class A

B. Class B

C. Class AB

D. Class C

Solution:

191. What is the phase difference between the output and the input voltage of a CE amplifier?

A. 180°

B. 270°

C. 0°

D. 90°

Solution:

192. Class C operation is preferred in oscillators because it

A. Is more efficient

B. Gives larger outputs

C. Produces square waves

D. Increases stability

Solution:

193. What type of oscillator which is composed of one or more amplifying devices with some frequency determining networks introducing positive feedback at a particular frequency so that oscillation is sustained at that frequency?

A. Sine wave oscillator

B. Square-wave generator

C. Relaxation oscillator

D. Limiter

Solution:

194. What is the desired input impedance of a transistor?

A. Low

B. Very low

C. High

D. Very high

Solution:

195. What is the maximum collector efficiency of class B?

A. 50%

B. 90%

C. 60.5%

D. 78.5%

Solution:

196. When a transistor is cut off

A. Maximum current flows

B. Maximum voltage appears across load

C. Maximum voltage appears across transistor

D. Minimum current flows

Solution:

197. In an LC circuit, when the capacitor energy is maximum, the inductor energy is

A. Maximum

B. Minimum

C. Half-way between maximum and minimum

D. Zero

Solution:

198. What is the approximate gain of an amplifier with negative feedback?

A. The feedback factor

B. The reciprocal of feedback factor plus one

C. The reciprocal of feedback factor

D. The feedback factor plus one

Solution:

199. The operating point in a transistor amplifier moves along ___________ when an ac signal is applied

C. both dc and ac load lines

D. cut-off

Solution:

200. An oscillator converts

A. ac power into dc power

B. dc power into ac power

C. mechanical power into ac power

D. electrical power into mechanical power

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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