Article: The printed circuit board industry defines heavy copper as layers exceeding three ounces of copper, or approximately 0.0042 inches (4.2 mils, 105 μm) thick. PCB designers and fabricators often use heavy copper when design and manufacturing circuit boards in order to increase current-carrying capacity as well as resistance to thermal strains. Heavy copper plated vias transfer heat to external heat sinks. IPC 2152 is a standard for determining current-carrying capacity of printed circuit board traces.

Question: What's the minimum amount of copper a layer in a PCB can have to be considered "heavy copper"?
Ans: three ounces


Article: Following the earthquake, donations were made by people from all over mainland China, with booths set up in schools, at banks, and around gas stations. People also donated blood, resulting in according to Xinhua long line-ups in most major Chinese cities. Many donated through text messaging on mobile phones to accounts set up by China Unicom and China Mobile By May 16, the Chinese government had allocated a total of $772 million for earthquake relief so far, up sharply from $159 million from May 14.

Question: How much had the Chinese government designated by May 16?
Ans: $772 million


Article: In 2004, worldwide sales of audio CDs, CD-ROMs and CD-Rs reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide. CDs are increasingly being replaced by other forms of digital storage and distribution, with the result that audio CD sales rates in the U.S. have dropped about 50% from their peak; however, they remain one of the primary distribution methods for the music industry. In 2014, revenues from digital music services matched those from physical format sales for the first time.

Question: What percent decrease did audio CD sales experience?
Ans: 50%


Article: Congress often enacts statutes that grant broad rulemaking authority to federal agencies. Often, Congress is simply too gridlocked to draft detailed statutes that explain how the agency should react to every possible situation, or Congress believes the agency's technical specialists are best equipped to deal with particular fact situations as they arise. Therefore, federal agencies are authorized to promulgate regulations. Under the principle of Chevron deference, regulations normally carry the force of law as long as they are based on a reasonable interpretation of the relevant statutes.

Question: Regulations normally carry the force of what?
Ans:
law