Here is a question about this article: Consider a half-wave dipole designed to work with signals 1 m wavelength, meaning the antenna would be approximately 50 cm across. If the element has a length-to-diameter ratio of 1000, it will have an inherent resistance of about 63 ohms. Using the appropriate transmission wire or balun, we match that resistance to ensure minimum signal loss. Feeding that antenna with a current of 1 ampere will require 63 volts of RF, and the antenna will radiate 63 watts (ignoring losses) of radio frequency power. Now consider the case when the antenna is fed a signal with a wavelength of 1.25 m; in this case the reflected current would arrive at the feed out-of-phase with the signal, causing the net current to drop while the voltage remains the same. Electrically this appears to be a very high impedance. The antenna and transmission line no longer have the same impedance, and the signal will be reflected back into the antenna, reducing output. This could be addressed by changing the matching system between the antenna and transmission line, but that solution only works well at the new design frequency.
What is the answer to this question: How could the rection of output be adressed by?
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So... changing the matching system


Here is a question about this article: Four boarders at his parents' apartments became Chopin's intimates: Tytus Woyciechowski, Jan Nepomucen Białobłocki, Jan Matuszyński and Julian Fontana; the latter two would become part of his Paris milieu. He was friendly with members of Warsaw's young artistic and intellectual world, including Fontana, Józef Bohdan Zaleski and Stefan Witwicki. He was also attracted to the singing student Konstancja Gładkowska. In letters to Woyciechowski, he indicated which of his works, and even which of their passages, were influenced by his fascination with her; his letter of 15 May 1830 revealed that the slow movement (Larghetto) of his Piano Concerto No. 1 (in E minor) was secretly dedicated to her – "It should be like dreaming in beautiful springtime – by moonlight." His final Conservatory report (July 1829) read: "Chopin F., third-year student, exceptional talent, musical genius."
What is the answer to this question: What four boys from his family's boarding house became friends with Chopin?
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So... Tytus Woyciechowski, Jan Nepomucen Białobłocki, Jan Matuszyński and Julian Fontana


Here is a question about this article: Since before 2000 BC, humans have utilized pesticides to protect their crops. The first known pesticide was elemental sulfur dusting used in ancient Sumer about 4,500 years ago in ancient Mesopotamia. The Rig Veda, which is about 4,000 years old, mentions the use of poisonous plants for pest control. By the 15th century, toxic chemicals such as arsenic, mercury, and lead were being applied to crops to kill pests. In the 17th century, nicotine sulfate was extracted from tobacco leaves for use as an insecticide. The 19th century saw the introduction of two more natural pesticides, pyrethrum, which is derived from chrysanthemums, and rotenone, which is derived from the roots of tropical vegetables. Until the 1950s, arsenic-based pesticides were dominant. Paul Müller discovered that DDT was a very effective insecticide. Organochlorines such as DDT were dominant, but they were replaced in the U.S. by organophosphates and carbamates by 1975. Since then, pyrethrin compounds have become the dominant insecticide. Herbicides became common in the 1960s, led by "triazine and other nitrogen-based compounds, carboxylic acids such as 2,4-dichlorophenoxyacetic acid, and glyphosate".
What is the answer to this question: What decade did herbicides become common?
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So...
1960s