MCQ in Modulation Part 12 | ECE Board Exam

(Last Updated On: February 24, 2021)

MCQ in Modulation Part 12 | ECE Board Exam

This is the Multiples Choice Questions Part 12 of the Series in Modulation as one of the Communications 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 Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

MCQ Topic Outline included in ECE Board Exam Syllabi

  • MCQ in Amplitude Modulation
  • MCQ in Phase Modulation
  • MCQ in Sound Pressure Level
  • MCQ in Frequency Modulation
  • MCQ in Pulse Modulation

Continue Practice Exam Test Questions Part 12 of the Series

551. In the phasing method of SSB generation, one sideband is cancelled due out to

a. phase shift

b. sharp selectivity

c. carrier suppression

d. phase inversion

View Answer:

Answer: Option A

Solution:

552. It is caused by poor front-end selectivity or inadequate image frequency rejection.

a. optimal coupling

b. double spotting

c. spurious pointing

d. under coupling

View Answer:

Answer: Option B

Solution:

553. It is a high-gain, low noise, tuned amplifier that, when used is the first active encountered by the receiver signal.

a. mixer

b. local oscillator

c. RF amplifier

d. detector

View Answer:

Answer: Option C

Solution:

554. It is a high performance microwave receiver at the input stage. In the RF section of optimize their noise figure.

a. high-power amplifier

b. low noise amplifier

c. buffer amplifier

d. local oscillator

View Answer:

Answer: Option B

Solution:

555. A balanced modulator used to demodulates a SSB signal is called

a. transponder

b. product detector

c. converter

d. modulator

View Answer:

Answer: Option B

Solution:

556. Which of the following is not the other name of a balanced modulator?

a. balanced mixer

b. product detector

c. product modulator

d. none of these

View Answer:

Answer: Option D

Solution:

557. ________ amplifiers are relatively high gain tuned amplifiers that are very similar to RF amplifiers, except that it operates over a relatively narrow, fixed frequency band.

a. IF amplifiers

b. low-noise amplifiers

c. buffer amplifiers

d. high-power amplifier

View Answer:

Answer: Option A

Solution:

558. Type of tuned circuit where both the primary and secondary sides of the transformer are tuned tank circuits

a. RLC tuned circuit

b. double-tuned circuit

c. single-tuned circuit

d. LC tuned circuit

View Answer:

Answer: Option B

Solution:

559. Frequency translation is done with a circuit called _______.

a. summer

b. multiplier

c. filter

d. mixer

View Answer:

Answer: Option D

Solution:

560. Low noise RF amplifiers use what type biasing?

a. class A

b. class B

c. class AB

d. class C

View Answer:

Answer: Option A

Solution:

561. Its purpose is to down-convert the incoming radio frequencies to intermediated frequencies.

a. local oscillator

b. RF amplifier

c. detector

d. mixer

View Answer:

Answer: Option D

Solution:

562. It is a non-linear amplifier similar to modulator, except that the output is turned to different between the RF and local oscillator frequencies.

a. RF amplifier

b. local oscillator

c. mixer

d. detector

View Answer:

Answer: Option C

Solution:

563. Mixing for frequency conversion is the same as

a. rectification

b. AM

c. linear summing

d. filtering

View Answer:

Answer: Option B

Solution:

564. The most common technique used for coupling IF amplifiers

a. resistive coupling

b. inductive coupling

c. capacitive coupling

d. direct coupling

View Answer:

Answer: Option B

Solution:

565. When the modulation index of an AM wave doubled, the antenna current is also doubled. The AM system being used is

a. single-sideband, full carrier (H3E)

b. vestigial sideband (C3F)

c. single sideband, suppressed carrier (J3E)

d. double sideband, full carrier (A3E)

View Answer:

Answer: Option C

Solution:

566. The ability of a coil to induce a voltage within its own windings is called

a. mutual inductance

b. coefficient coupling

c. self- inductance

d. inductance

View Answer:

Answer: Option C

Solution:

567. If the carrier of a 100 percent modulated AM wave is suppressed the percentage power saving will be

a. 50

b. 150

c. 100

d. 66.66

View Answer:

Answer: Option D

Solution:

568. The ability of one coil to induce a voltage in another coil is called _________.

a. coefficient coupling

b. mutual inductance

c. inductance

d. self-inductance

View Answer:

Answer: Option B

Solution:

569. Which of the following cam be used as a mixer?

a. balanced modulator

b. FET

c. diode modulator

d. all of the above

View Answer:

Answer: Option D

Solution:

570. It is the ratio of the secondary flux to primary flux

a. Q factor

b. coefficient coupling

c. self-inductance

d. coefficient of modulation

View Answer:

Answer: Option B

Solution:

571. Type of coupling where the secondary voltage is relatively low and the bandwidth is narrow.

a. tight coupling

b. optimum coupling

c. loose coupling

d. critical coupling

View Answer:

Answer: Option C

Solution:

572. An AM signal, transmitted information is contained within the

a. carrier

b. modulating signal

c. sidebands

d. envelope

View Answer:

Answer: Option C

Solution:

573. Type of coupling which has high gain and a broad bandwidth

a. optimum coupling

b. tight coupling

c. double coupling

d. loose coupling

View Answer:

Answer: Option B

Solution:

574. It is the point where the reflected resistance is equal to primary resistance and the Q of the primary tank circuit is halved and the bandwidth doubled.

a. critical coupling

b. tight coupling

c. loose coupling

d. optimum coupling

View Answer:

Answer: Option A

Solution:

575. The desired output from a mixer is usually selected with a

a. phase-shift circuit

b. crystal filter

c. resonant circuit

d. transformer

View Answer:

Answer: Option C

Solution:

576. It is caused by the reactive element of the reflected impedance being significant enough to change the resonant frequency of the primary tuned circuit.

a. optimum coupling

b. critical coupling

c. double peaking

d. flux linkage

View Answer:

Answer: Option C

Solution:

577. IF transformers come as specially designed tuned circuits in groundable metal packages called _______.

a. IF cans

b. IF container

c. IF strip

d. IF tetrapack

View Answer:

Answer: Option A

Solution:

578. The AM detector is sometimes called _______.

a. first detector

b. third detector

c. second detector

d. fourth detector

View Answer:

Answer: Option C

Solution:

579. The mixer is sometimes called _________.

a. first detector

b. third detector

c. second detector

d. fourth detector

View Answer:

Answer: Option A

Solution:

580. The two inputs to a mixer are the signal to be translated and a signal from

a. modulator

b. filter

c. antenna

d. local oscillator

View Answer:

Answer: Option D

Solution:

581. AM demodulator is commonly called _________.

a. phase detector

b. peak detector

c. frequency detector

d. transistor detector

View Answer:

Answer: Option B

Solution:

582. A type of detector that detects the shape of the input envelope

a. peak detector

b. phase detector

c. diode detector

d. shape detector

View Answer:

Answer: Option D

Solution:

583. The ratio of the peak modulating signal voltage to the peak carrier voltage is referred to as

a. voltage ratio

b. decibels

c. modulation index

d. mix factor

View Answer:

Answer: Option C

Solution:

584. A circuit that automatically increases the receiver gain for weak RF input levels and automatically decreases the receiver gain when a strong RF signal is received.

a. automatic volume control

b. automatic frequency control

c. automatic gain control

d. automatic phase control

View Answer:

Answer: Option C

Solution:

585. Which is not a type of AGC?

a. simple AGC

b. forward AGC

c. delayed AGC

d. complex AGC

View Answer:

Answer: Option D

Solution:

586. The value Vmax and Vmin as read from AM wave on an oscilloscope are 3.0 and 2.8. The percentage of modulation is

a. 10 percent

b. 41.4 percent

c. 80.6 percent

d. 93.3 percent

View Answer:

Answer: Option C

Solution:

587. Amplitude modulation is used for broadcasting because

a. it is more noise immune than other modulation systems

b. compared to other systems it requires less transmitting power

c. its use avoids receiver complexity

d. no other modulation system can provide the necessary bandwidth for high fidelity

View Answer:

Answer: Option C

Solution:

588. Type of AGC that prevents the AGC feedback voltage from reaching the RF or IF amplifiers until the RF level exceeds a predetermined magnitude.

a. forward AGC

b. delayed AGC

c. complex AGC

d. simple AGC

View Answer:

Answer: Option B

Solution:

589. A circuit with a purpose to quiet a receiver in the absence of a received signal.

a. automatic gain control

b. automatic frequency control

c. squelch circuit

d. automatic volume control

View Answer:

Answer: Option C

Solution:

590. A section of a audio stage of a receiver that removes sporadic, high amplitude noise transients of short duration, such as impulse noise.

a. squelch circuit

b. clampers

c. clippers

d. peak detector

View Answer:

Answer: Option C

Solution:

591. A circuit that detects the occurrence of a high-amplitude, short duration noise spike then mutes the receiver by shutting off a portion of the receiver of the duration of the pulse.

a. squelch circuit

b. limiter

c. clamper

d. blanking circuit

View Answer:

Answer: Option D

Solution:

592. The opposite modulation is

a. reverse modulation

b. downward modulation

c. unmodulation

d. demodulation

View Answer:

Answer: Option D

Solution:

593. For good image-frequency rejection, what is the desired value of the intermediate frequency?

a. relatively low IF

b. very low IF

c. relatively high IF

d. very high IF

View Answer:

Answer: Option C

Solution:

594. With high-gain selective amplifiers that are stable and easily neutralized. what is the desired value of intermediate frequency?

a. low IF

b. medium IF

c. high IF

d. very high IF

View Answer:

Answer: Option A

Solution:

595. It is defined as the ratio of the demodulated signal level at the output receiver to the RF signal level at the input to the receiver.

a. received signal level

b. figure of merit

c. effective radiated power

d. net receiver gain

View Answer:

Answer: Option D

Solution:

596. It is the process of modifying the characteristic of one signal in accordance with some characteristic of another signal.

a. multiplexing

b. mixing

c. modulation

d. summing

View Answer:

Answer: Option C

Solution:

597. The imaginary line on the carrier waveform of the amplitude modulated signal is called __________.

a. sidebands

b. envelope

c. spurious emission

d. information

View Answer:

Answer: Option B

Solution:

598. Indicate the false statement regarding the advantages of the phase cancellation method of obtaining SSB over the filter method is false:

a. more channel space available

b. transmitter circuits must be stable, giving better spectrum

c. the signal is more noise resistant

d. much less power is required for the same signal strength

View Answer:

Answer: Option B

Solution:

599. Indicate which one of the following advantages of the phase cancellation method of obtaining SSB over the filter method is false:

a. switching from one sideband to the other simpler

b. it is possible to generated SSB at any frequency

c. SSB with lower audio frequencies present can be generated.

d. There are more balanced modulators, therefore the carrier is suppressed better

View Answer:

Answer: Option D

Solution:

600. The most commonly used filters is SSB generation are

a. mechanical

b. RC

c. LC

d. low-pass

View Answer:

Answer: Option A

Solution:

Questions and Answers in Modulation Series

Following is the list of multiple choice questions in this brand new series:

MCQ in Modulation
PART 1: MCQ from Number 1 – 50                        Answer key: PART 1
PART 2: MCQ from Number 51 – 100                   Answer key: PART 2
PART 3: MCQ from Number 101 – 150                 Answer key: PART 3
PART 4: MCQ from Number 151 – 200                 Answer key: PART 4
PART 5: MCQ from Number 201 – 250                 Answer key: PART 5
PART 6: MCQ from Number 251 – 300                 Answer key: PART 6
PART 7: MCQ from Number 301 – 350                 Answer key: PART 7
PART 8: MCQ from Number 351 – 400                 Answer key: PART 8
PART 9: MCQ from Number 401 – 450                 Answer key: PART 9
PART 10: MCQ from Number 451 – 500                 Answer key: PART 10

Complete List of MCQ in Communications Engineering per topic

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