Problem: BJTs have three terminals, corresponding to the three layers of semiconductoran emitter, a base, and a collector. They are useful in amplifiers because the currents at the emitter and collector are controllable by a relatively small base current. In an npn transistor operating in the active region, the emitterbase junction is forward biased (electrons and holes recombine at the junction), and electrons are injected into the base region. Because the base is narrow, most of these electrons will diffuse into the reverse-biased (electrons and holes are formed at, and move away from the junction) basecollector junction and be swept into the collector; perhaps one-hundredth of the electrons will recombine in the base, which is the dominant mechanism in the base current. By controlling the number of electrons that can leave the base, the number of electrons entering the collector can be controlled. Collector current is approximately (common-emitter current gain) times the base current. It is typically greater than 100 for small-signal transistors but can be smaller in transistors designed for high-power applications.
Why is the base of a BJT narrow?
---
Answer: unanswerable

Problem: Hunting in the United States is not associated with any particular class or culture; a 2006 poll showed seventy-eight percent of Americans supported legal hunting, although relatively few Americans actually hunt. At the beginning of the 21st century, just six percent of Americans hunted. Southerners in states along the eastern seaboard hunted at a rate of five percent, slightly below the national average, and while hunting was more common in other parts of the South at nine percent, these rates did not surpass those of the Plains states, where twelve percent of Midwesterners hunted. Hunting in other areas of the country fell below the national average. Overall, in the 19962006 period, the number of hunters over the age of sixteen declined by ten percent, a drop attributable to a number of factors including habitat loss and changes in recreation habits.
What are recreation habits not associated with in the US?
---
Answer: unanswerable

Problem: His best known wife was Jovanka Broz. Tito was just shy of his 59th birthday, while she was 27, when they finally married in April 1952, with state security chief Aleksandar Rankovic as the best man. Their eventual marriage came about somewhat unexpectedly since Tito actually rejected her some years earlier when his confidante Ivan Krajacic brought her in originally. At that time, she was in her early 20s and Tito, objecting to her energetic personality, opted for the more mature opera singer Zinka Kunc instead. Not one to be discouraged easily, Jovanka continued working at Beli Dvor, where she managed the staff and eventually got another chance after Tito's strange relationship with Zinka failed. Since Jovanka was the only female companion he married while in power, she also went down in history as Yugoslavia's first lady. Their relationship was not a happy one, however. It had gone through many, often public, ups and downs with episodes of infidelities and even allegations of preparation for a coup d'etat by the latter pair. Certain unofficial reports suggest Tito and Jovanka even formally divorced in the late 1970s, shortly before his death. However, during Tito's funeral she was officially present as his wife, and later claimed rights for inheritance. The couple did not have any children.
How old was Jovanka Broz when she married Tito?
---
Answer:
27