(a(i))[1]
Explain the meaning of cross-linking.
(a(ii))[2]
Suggest why cross-linking in coaxial cables is much less than in wire pairs.
(b)[4]
A wire pair of length $1.4\,\text{km}$ is connected to a receiver, as shown in Fig. 12.1. The steady noise power in the wire pair is $3.8 \times 10^{-8}\,\text{W}$. If the input signal to the wire pair is $3.0 \times 10^{-3}\,\text{W}$, the signal-to-noise ratio at the receiver is $25\,\text{dB}$. Calculate the attenuation per unit length for the wire pair.