1) Calculate the field strength of radiated field generated at the distance of 1Km by a vertical wire of one-metre length in the direction at right angles to the axis of the wire, when it carries a current of 5A, at a frequency of 1MHz.
2) If effective height of the aerial is 1/100thwave emitted, find its radiation resistance.
3) An end fire array composed of the λ/2 radiator with axes at the right angles to the line of the array needed to have a power gain of
4) Determine the directivity of a broadside array of height 10 λ and length 20 λ in dB.
5) Write short note on the structure of:
a) Marconi antenna
b) Hertz antenna
6) Describe the benefits and drawbacks of the travelling wave antenna.
7) What is the critical frequency for the reflection at vertical incidence if maximum value of electron density is 1.24x106
8) A high frequency radio link has to be established between the two points on the earth 2000 Km away. If reflection region of the ionosphere is at a height of 200 Km and has a critical frequency of 6Hz. Determine the MUF for the given path.
9) Provide the methods for measuring the gain and beam width of the given antenna.
10) Explain the method to determine the radiation efficiency of the antenna.