A coaxial cable is made of two brass conductors. The spacing between the conductors is filled with Teflon $$\left( {{\varepsilon _r} = 2.1,\,\,\tan \,\,\delta = \,0} \right)$$. Which one of the following circuits can represent the lumped element model of a small piece of this cable having length $$\Delta \,\,z\,\,?$$

In the following figure, the transmitter Tx sends a wideband modulated RF signal via a coaxial cable to the receiver Rx. The output impedance $${Z_T}$$ of Tx, the characteristic impedance $${Z_0}$$ of the cable and the input impedance $${Z_R}$$ of Rx are all real. Which one of the following statements is TRUE about the distortion of the received signal due to impedance mismatch?

To maximize power transfer, a lossless transmission line is to be matched to a resistive load impedance via a $$\lambda /4$$ transformer as shown.

The return loss of a device is found to be 20 dB. The voltage standing wave ratio (VSWR) and magnitude of reflection coefficient are respectively.