Question: Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using power electronics). Thus both systems are faced with the same task: converting and transporting high-voltage AC from the power grid to low-voltage DC in the locomotive. Where should this conversion take place and at what voltage and current (AC or DC) should the power flow to the locomotive? And how does all this relate to energy-efficiency? Both the transmission and conversion of electric energy involve losses: ohmic losses in wires and power electronics, magnetic field losses in transformers and smoothing reactors (inductors). Power conversion for a DC system takes place mainly in a railway substation where large, heavy, and more efficient hardware can be used as compared to an AC system where conversion takes place aboard the locomotive where space is limited and losses are significantly higher. Also, the energy used to blow air to cool transformers, power electronics (including rectifiers), and other conversion hardware must be accounted for.
Is there an answer to this question: What doesn't involve losses?

Answer: unanswerable


Question: The English language has been official in the state of Oklahoma since 2010. The variety of North American English spoken is called Oklahoma English, and this dialect is quite diverse with its uneven blending of features of North Midland, South Midland, and Southern dialects. In 2000, 2,977,187 Oklahomans—92.6% of the resident population five years or older—spoke only English at home, a decrease from 95% in 1990. 238,732 Oklahoma residents reported speaking a language other than English in the 2000 census, about 7.4% of the total population of the state. Spanish is the second most commonly spoken language in the state, with 141,060 speakers counted in 2000. The next most commonly spoken language is Cherokee, with about 22,000 speakers living within the Cherokee Nation tribal jurisdiction area of eastern Oklahoma. Cherokee is an official language in the Cherokee Nation tribal jurisdiction area and in the United Keetoowah Band of Cherokee Indians.
Is there an answer to this question: When did Oklahoma declare an official language?

Answer: 2010


Question: An estimated 20,000 Somalis emigrated to the U.S. state of Minnesota some ten years ago and the Twin Cities (Minneapolis and Saint Paul) now have the highest population of Somalis in North America. The city of Minneapolis hosts hundreds of Somali-owned and operated businesses offering a variety of products, including leather shoes, jewelry and other fashion items, halal meat, and hawala or money transfer services. Community-based video rental stores likewise carry the latest Somali films and music. The number of Somalis has especially surged in the Cedar-Riverside area of Minneapolis.
Is there an answer to this question: Along with Saint Paul, what city constitutes the Twin Cities?

Answer: Minneapolis


Question: At times when a death sentence is affirmed on direct review, it is considered final. Yet, supplemental methods to attack the judgment, though less familiar than a typical appeal, do remain. These supplemental remedies are considered collateral review, that is, an avenue for upsetting judgments that have become otherwise final. Where the prisoner received his death sentence in a state-level trial, as is usually the case, the first step in collateral review is state collateral review. (If the case is a federal death penalty case, it proceeds immediately from direct review to federal habeas corpus.) Although all states have some type of collateral review, the process varies widely from state to state. Generally, the purpose of these collateral proceedings is to permit the prisoner to challenge his sentence on grounds that could not have been raised reasonably at trial or on direct review. Most often these are claims, such as ineffective assistance of counsel, which requires the court to consider new evidence outside the original trial record, something courts may not do in an ordinary appeal. State collateral review, though an important step in that it helps define the scope of subsequent review through federal habeas corpus, is rarely successful in and of itself. Only around 6 percent of death sentences are overturned on state collateral review. In 2010, the death sentences of 53 inmates were overturned as a result of legal appeals or high court reversals.
Is there an answer to this question: About what percentage of capital convictions are overturned due to state collateral review?

Answer:
6