Here is a question about this article: A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current in the opposite direction. Most materials used in antennas meet these conditions, but some microwave antennas use high-tech components such as isolators and circulators, made of nonreciprocal materials such as ferrite. These can be used to give the antenna a different behavior on receiving than it has on transmitting, which can be useful in applications like radar.
What is the answer to this question: How can the lack of this quality be used in an everyday way?
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So... radar


Here is a question about this article: Tourism, especially religious tourism, is an important industry in Israel, with the country's temperate climate, beaches, archaeological, other historical and biblical sites, and unique geography also drawing tourists. Israel's security problems have taken their toll on the industry, but the number of incoming tourists is on the rebound. In 2013, a record of 3.54 million tourists visited Israel with the most popular site of attraction being the Western Wall with 68% of tourists visiting there. Israel has the highest number of museums per capita in the world.
What is the answer to this question: How many tourists visited Israel in 2013?
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So... 3.54 million


Here is a question about this article: Each trace consists of a flat, narrow part of the copper foil that remains after etching. The resistance, determined by width and thickness, of the traces must be sufficiently low for the current the conductor will carry. Power and ground traces may need to be wider than signal traces. In a multi-layer board one entire layer may be mostly solid copper to act as a ground plane for shielding and power return. For microwave circuits, transmission lines can be laid out in the form of stripline and microstrip with carefully controlled dimensions to assure a consistent impedance. In radio-frequency and fast switching circuits the inductance and capacitance of the printed circuit board conductors become significant circuit elements, usually undesired; but they can be used as a deliberate part of the circuit design, obviating the need for additional discrete components.
What is the answer to this question: Along with thickness, what determines the resistance of a trace?
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So...
width