Problem: Large brushes are desired for a larger brush contact area to maximize motor output, but small brushes are desired for low mass to maximize the speed at which the motor can run without the brushes excessively bouncing and sparking. (Small brushes are also desirable for lower cost.) Stiffer brush springs can also be used to make brushes of a given mass work at a higher speed, but at the cost of greater friction losses (lower efficiency) and accelerated brush and commutator wear. Therefore, DC motor brush design entails a trade-off between output power, speed, and efficiency/wear.
Besides wear, what is a upside of stiff brush springs?
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Answer: unanswerable

Problem: China's first imperial dynasty was the Qin dynasty (221206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xiang Yu (d. 202 BC) of Chu and Liu Bang (d. 195 BC) of Han, engaged in a war to decide who would become hegemon of China, which had fissured into 18 kingdoms, each claiming allegiance to either Xiang Yu or Liu Bang. Although Xiang Yu proved to be a capable commander, Liu Bang defeated him at Battle of Gaixia (202 BC), in modern-day Anhui. Liu Bang assumed the title "emperor" (huangdi) at the urging of his followers and is known posthumously as Emperor Gaozu (r. 202195 BC). Chang'an was chosen as the new capital of the reunified empire under Han.
Who urged Liu Bang to become emperor?
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Answer: his followers

Problem: Since the late 18th century, Sanskrit has been transliterated using the Latin alphabet. The system most commonly used today is the IAST (International Alphabet of Sanskrit Transliteration), which has been the academic standard since 1888. ASCII-based transliteration schemes have also evolved because of difficulties representing Sanskrit characters in computer systems. These include Harvard-Kyoto and ITRANS, a transliteration scheme that is used widely on the Internet, especially in Usenet and in email, for considerations of speed of entry as well as rendering issues. With the wide availability of Unicode-aware web browsers, IAST has become common online. It is also possible to type using an alphanumeric keyboard and transliterate to Devanagari using software like Mac OS X's international support.
What system of transliteration is not commonly used on the internet or e-mail?
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Answer:
unanswerable