The advantages of optical fiber communication over a two-wire transmission line or coaxial cable are . . . . . . .

Given below are two statements:
Statement-$I$: $A$ speech signal of $2 \, kHz$ is used to modulate a carrier signal of $1 \, MHz$. The bandwidth requirement for the signal is $4 \, kHz$.
Statement-$II$: The sideband frequencies are $1002 \, kHz$ and $998 \, kHz$.
In the light of the above statements,choose the correct answer from the options given below:

The relationship between the maximum electron density $(N_{max})$ of the ionosphere and the critical frequency $(f_c)$ is given by:

What are the primary causes of signal attenuation in an optical fiber?

$A$ transmitting antenna at the top of a tower has height $32\, m$ and the height of the receiving antenna is $50\, m$. What is the maximum distance between them for satisfactory communication in line of sight $(LOS)$ mode? ........$km$

$A$ baseband signal of $3.5\, MHz$ frequency is modulated with a carrier signal of $3.5\, GHz$ frequency using amplitude modulation. What should be the minimum size of antenna required to transmit the modulated signal?