Answer Happy

Q5. (a) Starting with a general expression for a wave propagation constant y = jo us (1-j=)): (i) find an approximate expression for a and for in the case of a good conductor; 7 marks (ii) use the expression for a and for in the case of a good conductor and find their numerical values for the copper by assuming a = 6 *x107 (S/m) and μ = 1.25 x 10€ (H/m) when the frequency of the propagating wave is f = 1 kHz. 3 marks (b) A transmission line has the following line parameters. R' = 02m¹, L = 0.75 µHm-¹, G' = 0 Sm ¹and C' = 133 pFm-¹. The line has a length 1 = 93 m. A sinusoidal signal with a frequency of 10 MHz is inserted by a generator at the sending end of the line and the receiving end of the line is terminated with a load R₁ = 50 2. (i) From the line parameters, would you expect the line to behave as a "lossy line" or as a "distortionless line" or as a "lossless line"? 1 mark (ii) Calculate the values of the attenuation coefficient a, the phase constant and the characteristic impedance of the line. 4 marks (iii) Calculate the input impedance of the line. 3 marks (iv) To make the input impedance of the line equal to the load impedance, what is the smallest required reduction in the length of the line? 2 marks