A signal of \( 0.1 \, \text{kW} \) is transmitted in a cable. The attenuation of cable is \( -5 \, \text{dB per km} \) and cable length is \( 20 \, \text{km} \). The power received at receiver is \( 10^{-x} \, \text{W} \). The value of \( x \) is ______.
\([ \text{Gain in dB} = 10 \log_{10}\left(\dfrac{P_{0}}{P_{i}}\right) ]\)
