Coding Native Guy

Communication Systems Preparation Part 3 It is desired that transmission line and load should match for a range of frequencies. The best method is To use a double stub. When matching over a range of frequencies is desired, double stub is necessary. Which of the following has the highest input impedance? CC connection has very high input impedance and low output impedance In a fascimile reproduction time to scan one line is 2 ms. If it has 4% blanking, the visible trace time is 1.92 ms. (2 ms) (1 - 0.04) = 1.92 ms Consider the following statements The amplitude of an FM wave is constant FM is more immune to noise than AM FM broadcasts operate in upper VHF and UHF frequency ranges FM transmitting and receiving equipments are simpler as compared to AM transmitting and receiving equipments Which of the above are correct? B. FM equipments are complex as compared to AM equipments. Signal to noise

Communication Systems Preparation Part 2 In radar systems PRF stands for PRF in radar systems means pulse repetition frequency. Which of the following cannot be the Fourier series expansion of a periodic signal? x(t) = cos t + 0.5 not satisfies the Dirichlet condition. The integration of constant term is ∞ Which of the following is the indirect way of FM generation? Armstrong modulator generates FM through phase modulation. A telephone exchange has 9000 subscribers. If the number of calls originating at peak time is 10, 000 in one hour, the calling rate is 10/9. Calling rate is the number of calls per subscriber. If C is capacity of noisy channel, (bits/s), δf is bandwidth Hz and S/N is signal to noise ratio, then bandwidth multiply by sum of 1 and signal to noise ratio As the frequency increases, the absorption of ground wave by earth's surface Increases. Because of this

Communication Systems Preparation Part 1 A cordless telephone using separate frequencies for transmission in base and portable units is known as Duplex Arrangement. Separate frequencies for transmission from base and portable units allows two way transmission and is called duplex arrangement For attenuation of high frequencies we should use Shunt capacitance. Since Xc for high frequencies is low, the high frequencies are shunted to ground and are not transmitted. A modem is classified as low speed if data rate handled is Upto 600 bps. When data rate in bits per second is upto 600, modem is low speed. VSB modulation is preferred in TV because It reduces the bandwidth requirement to half. VSB (vestigial side band) transmission transmits one side band fully and the other side band partially thus, reducing the bandwidth requirement A woofer should be fed from the input through a Low pass filter. Woofer