Context and question: According to the commentators, Virgil received his first education when he was five years old and he later went to Cremona, Milan, and finally Rome to study rhetoric, medicine, and astronomy, which he soon abandoned for philosophy. From Virgil's admiring references to the neoteric writers Pollio and Cinna, it has been inferred that he was, for a time, associated with Catullus' neoteric circle. However schoolmates considered Virgil extremely shy and reserved, according to Servius, and he was nicknamed "Parthenias" or "maiden" because of his social aloofness. Virgil seems to have suffered bad health throughout his life and in some ways lived the life of an invalid. According to the Catalepton, while in the Epicurean school of Siro the Epicurean at Naples, he began to write poetry. A group of small works attributed to the youthful Virgil by the commentators survive collected under the title Appendix Vergiliana, but are largely considered spurious by scholars. One, the Catalepton, consists of fourteen short poems, some of which may be Virgil's, and another, a short narrative poem titled the Culex ("The Gnat"), was attributed to Virgil as early as the 1st century AD.
What did Cinna study?
Answer: unanswerable
Context and question: The SI unit of pressure is the pascal (symbol Pa), but vacuum is often measured in torrs, named for Torricelli, an early Italian physicist (16081647). A torr is equal to the displacement of a millimeter of mercury (mmHg) in a manometer with 1 torr equaling 133.3223684 pascals above absolute zero pressure. Vacuum is often also measured on the barometric scale or as a percentage of atmospheric pressure in bars or atmospheres. Low vacuum is often measured in millimeters of mercury (mmHg) or pascals (Pa) below standard atmospheric pressure. "Below atmospheric" means that the absolute pressure is equal to the current atmospheric pressure.
During what years was mercury commonly in use?
Answer: unanswerable
Context and question: For air dielectric capacitors the breakdown field strength is of the order 2 to 5 MV/m; for mica the breakdown is 100 to 300 MV/m; for oil, 15 to 25 MV/m; it can be much less when other materials are used for the dielectric. The dielectric is used in very thin layers and so absolute breakdown voltage of capacitors is limited. Typical ratings for capacitors used for general electronics applications range from a few volts to 1 kV. As the voltage increases, the dielectric must be thicker, making high-voltage capacitors larger per capacitance than those rated for lower voltages. The breakdown voltage is critically affected by factors such as the geometry of the capacitor conductive parts; sharp edges or points increase the electric field strength at that point and can lead to a local breakdown. Once this starts to happen, the breakdown quickly tracks through the dielectric until it reaches the opposite plate, leaving carbon behind and causing a short (or relatively low resistance) circuit. The results can be explosive as the short in the capacitor draws current from the surrounding circuitry and dissipates the energy.
In what way is the dielectric used in order to cause the absolute breakdown voltage of capacitors to be limited?
Answer:
The dielectric is used in very thin layers