Chapter 13, Problem 13.1P

A 50 km communication line has the following parameters: series resistance (R) = 21.4 W/km series inductance (L) = 1.0 mH/km shunt capacitance (C) = 0.062 mF/km shunt conductance (G) = 0.868 mS/km The frequency is 796 Hz and the line is terminated to avoid reflection. If the power at the receiving end is to be –20 dB (6mW reference) and the sending end voltage is 362 V, determine the power at the sending end.

Estimate the corona loss for a three-phase, 110 kV, 50 Hz, 150 km long transmission line consisting of three conductors each of 10 mm diameter and spaced 2.5 m apart in an equilateral  triangle formation. The temperature of air is 40ºC and the atmospheric pressure is 750 mm of  mercury. Take irregularity factor as 0.89. Ionization of air may be assumed to take place at a maximum voltage gradient of 30 kV/cm.

The effective span of an antenna is 2.147 m2 at an operating frequency of 100MHz. The antenna has no conduction or dielectric loss. The input impedance of the antenna is 75Ω and it is connected to a 50Ω transmission line. Find the directionality of the antenna system. (The term "system" here refers to the effects of binding to the transmission line.) It will be assumed that there is no polarization loss.

A cellular radio transmitter has a power output of 3 W at 800 MHz. It uses an antenna with a gain of 3 dBi. The receiver is 5 km away, with antenna gain of 12 dBi. Ignoring feedline losses and mismatch, calculate (a) the EIRP in dBW  (b) the free space path loss,    (c) the power delivered to the receiver in W and dBm

If you double the impedance of a transmission line you will double the inductance per unit length. T or F. Can you explain why????

An Underground cable of length 40 Km has a conductor of diameter of 1.5 cm and a sheath of inner diameter 5 cm. If the permittivity of insulation is 3.5, Analyze the following Electrical Parameters of the UG-cables (i) the inductance per km length              (ii) capacitance per km length.               (iii) Natural impedance (Surge Impedance) and                                        (iv) velocity of propagation of the travelling waves.

An optical fiber link with a distance of 30km long has a loss of 0.3dB/km. a) Calculate the minimum optical power level that must be launched into the fiber to maintain an optical power level of 3.0W at the receiving end.b) Estimate the required input power if the fiber has a loss of 0.6dB/km.c) Differentiate, with the aid of diagrams, the types of these dispersions and its effect on the transmission distance. (i) Modal Dispersion(ii) Chromatic Dispersion(iii) Polarization Mode Dispersion

A 350 km transmission line has the following parameters: z = 0.0195 +j0.35 Ω/km y = j4.5 μS/km If the load served by the line is 300 MVA, with an fp of 0.8(-), at a voltage of 100√3KV say: 6. The value of the incident and reflected wave, as well as the total voltage, at a point 200 km away from the extreme load. 7. The voltage and current at the emitting end. 8. What would be the percentage error in the magnitude of the voltage VS if it is calculated with the lossless line model? lossless line model? Note that the accurate value is the one that takes losses into account.

As a technician, you are responsible for the construction of a 10km optical communication link between Pelonomi Hospital and National Hospital in Bloemfontein. The following link specifications are available:Transmitter output power: 15mWCommercially available optical cable length: 2kmOptical cable attenuation: 1.2dB/kmSplice attenuation: 0.1dB/kmLight transmitter-to-cable loss: 1.5dBCable-to-photo detector loss: 1.5dBSafety margin: 7dB Determine the minimum receiver sensitivity in microwatts needed to reliably detect a transmitted signal.