Context and question: Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the finished photomask was photolithographically reproduced onto a photoresist coating on the blank copper-clad boards.
Designers would rub on a dry transfer of what to make the process of laying out components simpler?
Answer: common component footprints
Context and question: Aerobic gymnastics (formally Sport Aerobics) involves the performance of routines by individuals, pairs, trios or groups up to 6 people, emphasizing strength, flexibility, and aerobic fitness rather than acrobatic or balance skills. Routines are performed for all individuals on a 7x7m floor and also for 12–14 and 15-17 trios and mixed pairs. From 2009, all senior trios and mixed pairs were required to be on the larger floor (10x10m), all groups also perform on this floor. Routines generally last 60–90 seconds depending on age of participant and routine category.
What is the minimum floor size allowed by the FIG?
Answer: unanswerable
Context and question: Last but not least the electric double-layer capacitor (now Supercapacitors) were invented. In 1957 H. Becker developed a "Low voltage electrolytic capacitor with porous carbon electrodes". He believed that the energy was stored as a charge in the carbon pores used in his capacitor as in the pores of the etched foils of electrolytic capacitors. Because the double layer mechanism was not known by him at the time, he wrote in the patent: "It is not known exactly what is taking place in the component if it is used for energy storage, but it leads to an extremely high capacity.".
In what part of the capacitor did Becker believe the charge was being stored?
Answer:
in the carbon pores