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Simply divide the deviation by the modulation frequency to arrive at the correct answer:

\begin{align} \text{modulation index} &= \frac{\text{deviation}}{\text{modulation frequency}} \\ &= \frac{3000 \text{ Hz}}{1000 \text{ Hz}} \\ &= 3 \end{align} --wileyj2956

In other words, the modulation index tells you how efficient the modulation is. An index of 1 would mean that a 1000 Hz signal would cause a deviation of 1000 Hz on either side of the carrier. In this example, it takes a bandwidth of three times the modulating frequency on each side of the carrier to carry the information, a modulation index of 3.

Mnemonic:
Modulation index=mod in=mod inverse=dom=
d over m
=deviation (one sideband) over modulating frequency

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The FM modulation index is equal to the ratio of the frequency deviation to the modulating frequency.

\begin{align} \text{modulation index} &= \frac{\text{frequency deviation}}{\text{modulation frequency}} \\ &= \frac{6\text{ kHz}}{2 \text{ kHz}}\\ &= 3 \end{align}

See: https://www.radio-electronics.com/info/rf-technology-design/fm-frequency-modulation/modulation-index-deviation-ratio.php

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The deviation ratio is the maximum carrier frequency deviation divided by the highest (maximum) audio modulating frequency: \[\text{deviation ratio}=\frac{\text{max. carrier frequency swing}}{\text{max. modulation frequency}}\]

The carrier frequency deviation is defined by the frequency swing relative to the carrier, in this case \(+5\) kHz or \(-5\) kHz, the maximum being \(5\) kHz. Therefore, the deviation ratio is:

\begin{align} \text{deviation ratio}&=\frac{5 \text{ kHz}}{3\text{ kHz}}\\ &=1.666...\approx1.67 \end{align}

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\begin{align} \text{deviation} &= \frac{\text{frequency swing}}{\text{frequency}}\\ &= \frac{7.5 \text{ kHz}}{3.5 \text{ kHz}}=2.142857...\\ &\approx 2.14 \end{align}

The deviation ratio is calculated by dividing the maximum deviation by the maximum modulation: \[ \frac{\text{maximum deviation}}{\text{maximum modulation frequency}}\]

The deviation ratio of an FM-phone signal having a maximum frequency swing of \(\pm\) 7.5 kHz when the maximum modulation frequency is 3.5 kHz is 2.14.

Hint: 7.5 kHz and 3.5 kHz are a couple [2] of deviants [KQ4AEY]

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Pulse-width modulation uses pulse widths to determine the absolute value of instantaneous power, and the average power P(ave) of such a (square-wave) system is defined as

P(ave) = [D X T X P(peak) + T X (1 - D) X P(low)] / T,

in which D = the duty cycle (range 0.0 to 1.0), T is the period, or complete cycle, P(low) is the minimum power, and P(peak) is the peak power. When the duty cycle D is 0.0 (0%), P(ave) = P(low), and when the duty cycle D is 1.0 (100%), P(ave) = P(peak). Therefore, as long as the duty cycle is less that 100%, the transmitter's average power will always be less than its peak power, or in other words, the transmitter's peak power will always be greater than its average power, so the answer is (A).

Even during modulation (whether it's a voice or spikes being modulated),the transmitter cannot reach peak amplitude so long as the duty cycle is less than 100% (which defines pulse-width modulation, since there is no 'modulation' when the pulse is infinitely wide), so (B) and (C) are incorrect.

As for modulating the pulses themselves, they are the tools, not the subject, of modulation, so (D) is also incorrect.

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TIP: It is the only answer that has 'deviation' in it.

In FM modulation, the two primary parameters of interest are deviation ratio and modulation index. Deviation ratio is the ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.

The deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz is 1.67.

The deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz is 2.14.

Mnemonic: Deviant child = (Swing carrying child to the max swing height) over (Maximum length of Odd Mud)

Hint: Only the question and the correct answer have 'deviation' in it.

Stupid Hint: You want the "Maximum" points on this question.

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http://en.wikipedia.org/wiki/Frequency-division_multiplexing

In frequency division multiplexing, a communication medium is divided into non-overlapping frequency sub-bands, which can be used to independently transmit separate information streams or to dependently transmit a single information stream in parallel.

Although a technically correct answer, the option looks at the question from the reverse of the way Frequency Division Multiplexing is normally thought of -- from the result, which is that the frequency band has been divided into separate streams, with each stream carrying part of the overall message. Describing it as, "Two or more information streams are merged into a baseband, which then modulates the transmitter" is intended to be confusing, but it is technically accurate.

At first blush, none of the answers appear correct, especially if you are already familiar with the encoding technique from data modems. Remember that this question requires reversing the thought process. Ignore the name of the method and realize that the way you get to the end result is by first splitting the information being sent (not stated in the question) into two or (often many) more data streams, then modulating each of the multiple streams into its own frequency segment of the transmitted signal.

Typically multiplexing implies transmitting two or more independent information streams (can be analog or digital) rather than splitting a single stream.

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Time division multiplexing (TDM) is a communications process that transmits two or more streaming digital signals over a common channel. In TDM, incoming signals are divided into equal fixed-length time slots. After multiplexing, these signals are transmitted over a shared medium and reassembled into their original format after de-multiplexing. Time slot selection is directly proportional to overall system efficiency.

Time division multiplexing (TDM) is also known as a digital circuit switched.

per https://www.techopedia.com/definition/9669/time-division-multiplexing-tdm

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Hint: The answer has time slot in it.

Hint: time division --> time slots

Hint: digital in question 'data transmission' last two words answer

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