The loss of strength of a signal while propagating through a medium is known as

$A$ basic communication system consists of:
$(a)$ Transmitter
$(b)$ Information source
$(c)$ User of information
$(d)$ Channel
$(e)$ Receiver
The correct sequence of the arrangement is:

Which of the following statements is $NOT$ true regarding communication through optical fibers?

$A$ $TV$ transmission antenna is $40 \ m$ tall. How much service area can it cover if the receiving antenna is at the ground level? (Radius of the Earth $= 6400 \ km$)

$A$ message signal of frequency $5\,kHz$ is used to modulate a carrier signal of frequency $2\,MHz$. The bandwidth for amplitude modulation is $..........\,kHz$.

$A$ transmitting antenna covers a range of $12.8 \ km$. Find the height of the antenna in $m$. (Radius of the Earth $= 6400 \ km$)