GATE EC Transmission Lines questions

Assuming perfect conductors of a transmission line, pure $\text{TEM}$ propagation is $\text{NOT}$ possible in

In air, a lossless transmission line of length $50 \mathrm{~cm}$ with $\mathrm{L}=10 \; \mu \mathrm{H} / \mathrm{m}, \mathrm{C}=40 \; \mathrm{pF} / \mathrm{m}$ is operated at $25 \; \mathrm{MHz}$. Its electrical path length is

A trasmitting antenna radiates $251 \mathrm{~W}$ isotropically. A receiving antenna, located $100 \mathrm{~m}$ away from the transmitting antenna, has an effective aperture of $500 \mathrm{~cm}^{2}$. The total received by the antenna is

In a twin-wire transmission line in air, the adjacent voltage maxima are at $12.5 \mathrm{~cm}$ and $27.5 \mathrm{~cm}$. The operating frequency is

A high-Q quartz crystal exhibits series resonance at the frequency $\omega_{s}$ and parallel resonance at the frequency $\omega_{p}$. Then

The far field of an antenna varies with distance $\mathrm{r}$ as

An antenna in free space receives $2 \; \mu \mathrm{W}$ of power when the incident electric field is $20 \mathrm{~m} \; \mathrm{V} / \mathrm{m} \; \mathrm{rms}$. The effective aperture of the antenna is

The radiation resistance of a circular loop of one turn is $0.01 \; \Omega$. The radiation resistance of five turns of such a loop will be

The vector $\mathrm{H}$ in the far field of an antenna satisfies

All transmission line sections shown in the figure is have a characteristic impedance $\text{R}_{0}+\text{j}_{0}$. The input impedance $\text{Z}_{\text{in}}$ equals

A rectangular air-filled waveguide has cross section of $4 \mathrm{~cm} \times 10 \mathrm{~cm}$. The minimum frequency which can propagate in the waveguide is

A transmission line of $50 \; \Omega$ characteristic impedance is terminated with a $100 \; \Omega$ resistance. The minimum impedance measured on the line is equal to

A very lossy, $\lambda / 4$ long, $50 \; \Omega$ transmission line is open circuited at the load end. The input impedance measured at the other end of the line is approximately

The capacitance per unit length and the characteristic impedance of a lossless transmission line are $\mathrm{C}$ and $\mathrm{Zo}$ respectively. The velocity of a travelling wave on the transmission line

A lossless transmission line having $50 \; \Omega$ charateristic impedance and lengh $\lambda / 4$ is short circuited at one end and connected to an ideal voltage source of $1 \mathrm{~V}$ at the other end. The current drawn from the voltage source is

An antenna, when radiating, has a highly directional radiation pattern. When the antenna is receiving, its radiation pattern

For a dipole antenna

Consider a transmission line of characteristic impedance of $50 \; \mathrm{ohm}$. Let it be terminated at one end by $+j \; 50 \; \mathrm{ohm}$. The $\text{VSWR}$ produced by it in the transmission line will be

In a multicavity magnetron, strapping is employed primarily

The beamwidth-between-first null of uniform linear array of $\mathrm{N}$ equally-spaced (element spacing $=d$ ), equally-excited antennas is determined by