One channel of communication is by the use of a coaxial cable. Such a cable is illustrated in the figure below.
Suggest the material from which the component labelled A on the figure above is made.
Suggest two functions of the component labelled A.
When a signal travels along the coaxial cable, it is attenuated.
State the meaning of attenuation.
State and explain why attenuation is frequently measured in decibels (dB).
A television aerial is connected to a receiver using a coaxial cable of length 
. The attenuation per unit length of the cable is 
. Calculate the ratio
) because 
