Question

Modulation is used to(i) reduce the bandwidth used(ii) separate the transmissions of different users
(iii) ensure that information may be transmitted to long distances
(iv) allow the use of practical antennas.

Answer 1

(iv) allow the use of practical antennas allow the use of practical antennas

Explanation:

There are two major purposes of modulation. First benefit is to send multiple signals on a single channel at different frequency bands as frequency is inversely proportional to the size of antenna. Moreover, modulation signal is modulated at high frequency. As a result, we have to put small antenna at the receiving end.