A satellite in geostationary orbit is used to transmit data via electromagnetic radiation. The satellite is at a height of 35,000 km above the surface of the earth, and we assume it has an isotropic power output of 1.0 kW (although, in practice, satellite antennas transmit signals that are less powerful but more directional) Part A Reception devices pick up the variation in the electric field vector of the electromagnetic wave sent out by the satellite. Given the satellite specifications listed in the problem introduction, what is the amplitude Eo of the electric field vector of the satellite broadcast as measured at the surface of the earth? Use € = 8.85 x 10-12 C/(V.m) for the permittivity of space and c = 3.00 x 10 m/s for the speed of light. Express the amplitude of the electric field vector in microvolts per meter to two significant figures. View Available Hint(s) Eo = 7.0 AV m Submit Previous Answers Correct AV Correct answer is shown. Your answer 6.99 was either rounded differently or used a different number of significant figures than required for this part. Part B Imagine that the satellite described in the problem introduction used to transmit television signals. You have a satellite TV reciever consisting of a circular dish of radius R which focuses the electromagnetic energy incident from the satellite onto a receiver which has surface area of 5 cm2 How large does the radius R of the dish have to be to achieve an electric field vector amplitude of 0.1 mV/m at the receiver? For simplicity, assume that your house is located directly beneath the satellite (i.e. the situation you calculated in the first part), that the dish reflects all of the incident signal onto the receiver, and that there are no losses associated with the reception process. The dish has a curvature, but the radius R refers to the projection of the dish into the plane perpendicular to the direction of the incoming signal. Give your answer in centimeters, to two significant figures. View Available Hint(s) IVO AO ? R= cm Submit
