Tuesday, September 07, 2010

Electronics Concepts

1. When a transmission line or waveguide is mismatched by a load, a standing wave is created in the line or the waveguide. The distance between two adjacent maxima or minima is one half of a wavelength.

2. The radius of Earth is 6378 KM.

3. Charge on one electron is 1.6 * 10 (pow -19) coulomb

4. Minimum 3 identical RC high-pass sections connected in cascade are required in a phase-shift oscillator.

5. In a microwave circuit with waveguides, a waveguide twist is used for rotating plane of polarization.

6. Microstrip line has the combined characteristics of dielectric, ohmic and radiation losses.

7. A duplexer uses same antenna for reception or transmission without interference.

8. X-band frequencies are in the range of 8.0 to 12.0 GHz.

9. The advantages of cycle stealing in DMA are:
      a. It increases the maximum I/O transfer rate.
      b. It reduces the interference by the DMA controllers in CPU's memory access.
      c. It is beneficially employed for I/O devices with shorter bursts of data transfer.

10. An FM radio station performs better than an AM station radiating the same total power as FM is immune to noise.

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