Context and question: In March 2003 the BBC announced that from the end of May 2003 (subsequently deferred to 14 July) it intended to transmit all eight of its domestic television channels (including the 15 regional variations of BBC 1) unencrypted from the Astra 2D satellite. This move was estimated to save the BBC 85 million over the next five years.
When did the switch to the Astra 2D satellite begin?
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.
Of what order is the breakdown field weakness for mica dielectric capacitors?
Answer: unanswerable
Context and question: In 1838 with the amount of smuggled opium entering China approaching 1,400 tons a year, the Chinese imposed a death penalty for opium smuggling and sent a Special Imperial Commissioner, Lin Zexu, to curb smuggling. This resulted in the First Opium War (183942). After the war Hong Kong island was ceded to Britain under the Treaty of Nanking and the Chinese market opened to the opium traders of Britain and other nations. The Jardines and Apcar and Company dominated the trade, although P&O also tried to take a share. A Second Opium War fought by Britain and France against China lasted from 1856 until 1860 and led to the Treaty of Tientsin, which legalised the importation of opium. Legalisation stimulated domestic Chinese opium production and increased the importation of opium from Turkey and Persia. This increased competition for the Chinese market led to India reducing its opium output and diversifying its exports.
in 1838 about how many tone of Opium was smuggled in to China per year?
Answer:
1,400 tons