电工电子专业英语 教学课件 ppt 作者 徐红梅 Unit7,8

,Exercises . Answer the following questions.,1. What is Ohms Law? 2. What is current? 3. What does R stands for? 4. What does P stands for? 5. What is the unit of power?,. Are the following statements correct? If the sentence is correct, say “True” aloud, if not, say “False”. 1. R stands for voltage which is a potential difference. 2. I is current, that is the flow of electrons. 3. Conductors like resistors and capacitors resist to some degree the flow of current. 4. The unit of current is Watt. 5. The power of an alternating current is its voltage multiplied by current.,. Translate the following sentences into Chinese. 1. Ohms Law is a mathematical expression of the relationship betwe-en voltage, current and resistance. 2. Current is the quantity of charge passing a given point in a unit of time in a circuit. 3. Conductors like resistors and capacitors resist to some degree the flow of current. 4. The work performed by an electrical current in a unit of time is called power. 5. The power of a direct current is its voltage multiplied by current.,Notes to the text 1. An inductor is an electrical device, which opposes a change in electrical current.注:句中which引导非限定定语从句,先行词是electrical device.,译:电感是阻碍电流变化的电装置。 2.Resistance offers an opposition to all current flow while inductance only offers an op-position to non-constant current flow. 注:此句中while 引导状语从句,译作“而” 。 译:电阻对所有的电流都产生阻碍作用,而电感只对有变化的电流产生阻碍作用。,Exercises . Answer the following questions. 1. What is an inductor? 2. What is the unit of inductance? 3. What are inductors used for? 4. What is inductance? 5. There are two types of inductors, what are they?,. Are the following statements correct? If the sentence is correct, say “True” aloud, if not, say “False”. 1. An inductor is a device that resists change in voltage. 2. An inductor usually has no resistance to AC current but has a high resistance to DC current. 3. An inductor is electrically opposite to the capacitor. 4. At certain frequency, if a coil offers a large opposition to the current, it has large in-ductance. 5. Inductance is represented by the letter M and measured in unit of Henry.,. Translate the following sentences into Chinese. An inductor is an electrical device, which opposes a change in electrical current. 2. It usually has no resistance to DC current but has a high resistance to AC current. 3. The inductor is a coil of wire that may have an air core or an iron core to increase it inductance. 4. Resistance offers an opposition to all current flow while inductance only offers an op-position to non-constant current flow. 5. The property of a conductor to oppose a change in current is known as inductance.,