An FM broadcast station has a transmitting antenna located 50 m above average terrain. How far away could the signal be received by a rooftop antenna 12 m above the ground? Ans: 43.44 km.

If the Average Power Density of an antenna is given as: 60sin (0) Wav = (WIm²) a) What is the value of the Average Power Density at (0 = 30°) and (r = 2 m) = %3D (W/m?) b) What is the value of the Radiation Intensity at (0 = 45°) and (r = 3 m) = %3D %3D (W/Steradian) c) What do we call an antenna that has repeated (more than one identical) elements?

A radar pulse returns to the transmitter–receiver after a total travel time of 4.00 3 1024 s. How far away is the object that reflected the wave?

Suppose the maximum safe average intensity of microwaves for human exposure is taken to be 1.00 W/m2. If a radar unit leaks 10.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away, ?min, must you be to be exposed to an average intensity considered to be safe? Assume that the power spreads uniformly over the area of a sphere with no complications from absorption or reflection. ?min=   m What is the maximum electric field strength ?0 at this distance? The permittivity of free space is ?0=8.854×10−12 C2/(N·m2). The speed of light is ?=3.00×108 m/s. ?0=   V/m Note: Early radar units leaked more than modern ones do. This caused identifiable health problems, such as cataracts, for people who worked near them.