Similar Question - Explain significance of modulation in communication.

Reduction in height of antenna:

For transmission of radio signals, the antenna height must be a multiple of $(λ/4)$. Here $λ$ is wavelength. $λ=C/f$ Where C is the velocity of light and f is the frequency of sig to be transmitted. The minimum antenna height required to transmit a baseband signal of $f=10 kHz$ is calculated as : - $=\frac{λ}{4}=\frac{C}{4f}=\frac{(3 \times 10^8)}{(4 \times 10 \times 10^3)} \ =7500 \text{meters}, i.e. , 7.5 km$

The antenna of this height is practically impossible to install.

Avoids mixing of signals:

If the baseband sound signal are transmitted without using the modulation by more than one transmitter, then all the transmitted signal by multiple transmitter will be in the same frequency. range, i.e., 0 to 20kHz

∴ The signals from different station get mixed together and a receiver cannot separate them from each other.

So if each baseband sound signal is used to modulate a different carrier which corresponds to a different station then they will occupy difft. Slots in frequency spectrum.

Increases the range of communication:

The frequency of baseband signals is low and the low frequency. signals cannot travel a long distance when they are transmitted. They get attennated (suppressed) quickly.

The attennation reduces with increase in frequency. of transmitted signals and they travel longer distance.

The modulation process increases the frequency. of signal. Hence it increases the range of communication.

Multiplexing becomes possible:

Multiplexing is a process in which two or more signals can be transmitted over the same comm. Channel simultaneously.

This is possible only with modulation. The multiplexing allows the channel to be used by many signals.

So many TV channels can use the same frequency. range, without getting mixed with each other. Or difft frequency. sigs can be transmitted at the same time.

Improve quality of reception:

With frequency. modulation (FM) and digital communication techniques like PCM, the effect of noise is reduced to a great extent. This improves quality of reception.