,Exercises . Answer the following questions. 1. What is a capacitor? 2. Why are capacitors widely used? 3. What is capacitance? 4. What is the unit of the capacitance? 5. How do you work out the total capacitance if we join two capacitors in parallel?,. Are the following statements correct? If the sentence is correct, say “True” aloud, if not, say “False”. 1. A capacitor is a device that resists change in current. 2. Capacitors are widely used because they resist change in voltage. 3. The values of capacitors are expressed in Farads. 4. If we join capacitors in series,the total capacitance is the sum of the individual capaci-tances. 5. The property to produce a current in a capacitor when the voltage across it changes is called capacitance.,. Translate the following sentences into Chinese. 1. A capacitor is an electrical device that can store electrical energy. 2. Basically a capacitor consists of two conductors separated by a nonconductor. 3. Capacitors are widely used because they can store electrical energy in a circuit, and they can pass alternating currents in circuit while blocking a direct current. 4. The property to produce a current in a capacitor when the voltage across it changes is called capacitance. 5. If we join capacitors in series,the total capacitance is less than the capacitance of the smallest capacitor.,Exercises . Answer the following questions. 1. What is a diode? 2. What is the P-N junction made of? 3. How many electrodes does a transistor have? 4. How many P-N junctions does a transistor have? 5. How many types of transistors are there?,. Are the following statements correct? If the sentence is correct, say “True” aloud, if not, say “False”,1. A diode is not the simplest semiconductor device. 2. The P-N junction is made of semiconductor material. 3. A diode is forward biased when the voltage of its anode is lower than the voltage of its cathode. 4. The P-type material is called the anode. 5. A transistor has three electrodes.,. Translate the following sentences into Chinese. 1. It is a two-terminal device containing a single P-N junction. 2. The P-N junction is made of semiconductor materials. 3. Transistors are made from three laerys of semiconductors. 4. The diode is reverse biased when voltage of its anode is lower than the voltage of its cathode. 5. A diode is the simplest semiconductor device.,5.现在分词与过去分词的区别 现在分词表示主动意义,表示正在进行的动作,而过去分词表示被动意义,表示已完成的动作。 e.g.Working with his friends, he succeeded in making the design. (现在分词作状语) 他与朋友们一起完成了设计。 Helped by his friends, he succeeded in making the design.(过去分词作状语) 在朋友们的帮助下,他完成了设计。,