专业英语大作业(张伟).doc

专业英语结课报告 姓名：张伟 班级：09电信统本01班 学号：091102010123 日期：2012/12/5 Summary of the physical electrical knowledge ?1 circuit ?1) the formation of the current: the directional movement of the charge formation current. (Directional movement will be the formation of any charge current). ?2) the current direction: negative flows from the positive power supply. ?3) Power: provide continuous current (or voltage) of the device. ?4) power supply is to the other forms of energy into electrical energy. Such as dry cell chemical energy into electrical energy. Generators from mechanical energy into electrical energy. ?5) continuous current conditions: power supply and the circuit is closed. ?6) conductor: easy conductive objects called conductors. Such as: metal, the body, the earth, aqueous salt solutions. ?7) Insulator: the conductive objects called insulators. Such as: glass, ceramics, plastics, oil, such as pure water. ?8) The circuit is composed of: from the power supply, wires, switches, and electrical appliances. ?9) Road three states: (1) path: ON circuit called pathway; (2) open: the disconnect circuit called open; (3) short-circuit: direct access to wire circuit called a short circuit on the power poles. ?10) schematic: schematic symbol indicates that the circuit connection diagram called. ?11) Series: linking the elements one by one in order, called the series. The (anywhere Disconnect current will disappear). ?12) in parallel: the components are connected in parallel, and called in parallel. (Each branch is independently of each other). (2) current ?1) international units: ampere (A); commonly used: milliamperes (mA), the microampere (A), 1 Amps = 103 mA = 106 microamperes. ?2) measuring the current meter is: ammeter, its use rule is: ① ammeter connected in series in the circuit; (2) current from the terminal into the + from - terminal; ③ measured current should not exceed ammeter range; ④ absolutely not allowed without the use of electrical appliances and the ammeter connect