Principles of Communication Mocktest (Midterms) BSIT 307

29問 • 1年前

問題一覧

is the process of converting raw message data into digital signals or waves over a modulator to optimize transmission. This process increases the strength of the signal to have maximum reach.

Modulation

is the steady waveform in terms of amplitude (height) and frequency

Carrier signal

it is the message that must be transmitted

Modulating Signal

is the output signal after the process.

Modulated Signal

One way to get a high-frequency signal to carry a low-frequency signal is by

Amplitude Modulation

It is a modulation process focused on modulating or changing the signal's amplitude.

Amplitude Modulation

are voltage or current variations that occur over time and are displayed on an oscilloscope screen

Time domain signals

During the modulation of a carrier wave by a modulating signal, new signals are generated at different frequencies as part of the process. These frequencies are called _____

Sidebands

Sideband signals are illustrated in a _________ where the horizontal axis represents frequency, and the vertical axis represents the signal’s magnitude, whether in voltage, current, or power amplitude.

Frequency domain

This is known as the ________, also referred to as the degree of modulation or modulating factor/coefficient.

modulation index

This is known as the ________, also referred to as the degree of modulation or modulating factor/coefficient.

modulation index

It can be used to derive the modulation index (𝑚) by measuring the values of the modulation and carrier voltages and then calculating the ratio.

oscilloscope

𝑽𝒎𝒂𝒙 is also known as

peak value

𝑽𝒎𝒊𝒏, the lowest, is also known as...

trough

AM means....

Amplitude Modulation

What is the formula for finding modulating index (𝑚)?

𝑉𝑚 / 𝑉𝑐 * 100

An imaginary line connects the positive and negative peaks of the carrier waveform. This imaginary line is called an ... ?

Envelope

A modulation process that puts the message in a carrier wave by changing the instantaneous frequency of the wave.

Frequency Modulation

It is the amount of change in the carrier frequency caused by the modulating signal. The maximum frequency deviation happens at the maximum amplitude of the modulating signal.

Frequency Deviation (𝒇𝒅)

The amount of shift depends on the amplitude of the binary signal. This modulation is called

frequency-shift keying

A modulation process wherein the phase of the carrier signal varies based on the amplitude variation of the message signal or modulating signal.

Phase Modulation

It starts to lead or compress at the second zero deviation until the next positive peak of the modulating signal. These are called _____?

lagging phase shifts and leading phase shifts

the signal does a 180°phase shift when it hits binary 1 or 0. The shift happens whether the signal is positive or negative. This process is called

phase-shift keying or binary phase-shift keying.

When a constant-frequency sine wave modulates a carrier, what is produced?

two side frequencies or sidebands

Which statement is NOT TRUE about Modulation

These are voltage or current variations that occur over time and are displayed on an oscilloscope screen.

Which statement is NOT TRUE about Sidebands

It is done to improve signals often unsuitable for the transmission device

Which statement is NOT TRUE about the characteristics of an Amplitude Modulation

The carrier frequency shifts proportionately as the modulating signal’s amplitude varies.

Which statement is NOT TRUE about the characteristics of an Frequency Modulation

An increase/decrease in the amplitude of the modulating signal causes an increase/decrease in the positive and negative peaks of the carrier amplitude.

Which statement is TRUE about Phase Modulation

A modulation process wherein the phase of the carrier signal varies based on the amplitude variation of the message signal or modulating signal.

The Contemporary World Mock test (Prelims)

Xai Alexandrei Delos Reyes · 58問 · 2年前

The Contemporary World Mock test (Prelims)