Embibe Experts Solutions for Exercise 3: Assignment

An information signal of $150 \mathrm{MHz}$ is to be sent across a distance of $40 \mathrm{km}.$ Which mode of communication is suitable?
$\left(\text{Radius of earth is}, R=6400 \mathrm{km}\right)$

Line of sight $\left(\mathrm{LOS}\right)$communication is also known as

If $\lambda$ is wavelength of radio signals to be transmitted, then the length of Hertz antenna is

Modulation is necessary

Modulation is done in

"Need for modulation" arises due to which of the following reasons?

An audio signal of $0.1 \mathrm{V}$ is used in amplitude modulation of a carrier wave of amplitude $0.3.$ The modulation index is

A photodetector is made from a compound semiconductor with band gap $0.73 \mathrm{eV}.$ The maximum wavelength it can detect is nearly