An electric-dipole antenna, broadcasting microwave electromagnetic radiation for

Question

An electric-dipole antenna, broadcasting microwave electromagnetic radiation for mobile communications, is located on the roof of a 127-m-high building and is oriented vertically. Two observers measure the signal strength (radiation intensity) from this antenna. Observer A is on the roof of another building, at the same height as the antenna and at a distance of 1.61 km from it. Observer B is on the street, with a direct-line distance of only 168 m from the antenna. What is the ratio of the signal strength measured by B, IB, to that measured by A, IA?

Note: the answers that I have input and have been incorrect are as follows:

1 - 0

2 - 58.81

3 - 7.67

4 - 0.017

5 - 58.44

6 - 18.8

7 - 91.84

8 - 0.011

9 - 18.797

10 - 0.00647

Explanation / Answer

sinA = sin90o = 1, sinB = 127/168

IB/IA = [RAsinB/RBsinA]2 = [1610 * (127/168) / (168 * 1)]2 = 52.48

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