Section A Pre-reading Electrical machines,transformers,and daily life Some common electrical machines and electrical equipment are shown in the An electrical machine is a device that following pictures and their names have can convert either mechanical energy to been given.Match the pictures with electrical energy or electrical energy to their corresponding names. mechanical energy.When such a device transformer contactor switch is used to convert mechanical energy to electric generator electric motor electrical energy,it is called a generator. relay When it converts electrical energy to mechanical energy,it is called a motor Since any given electrical machine can convert power in either direction,any machine can be used as either a generator ⊙ or a motor.Almost all practical motors and generators convert energy from one form to another through the action of a magnetic field.The transformer is an electrical device that is closely related to electrical machines.Since transformers operate on the same principles as generators and motors,depending on the action of a magnetic field to accomplish the change in voltage level,they are usually studied together with generators 2Discuss the following questions with your partner. and motors.These three types of electric devices are ubiquitous in modern daily 1.What is the function of an electrical machine?Tell the class the types life.Electric motors in the home run refrigerators,freezers,vacuum cleaners, of electrical machines and their applications that you know. blenders,air conditioners,fans,and many 2.How do you define electrical similar appliances.In the workplace. equipment?List some cases of the motors provide the motive power for use of electrical equipment in our daily life. 24 电气工程英语I SectionA I Pre-reading Some common electrical machines and electrical equipment are shown in the following pictures and their names have been given. Match the pictures with their corresponding names. transformer contactor switch electric generator electric motor relay - 必， ', Discuss the following questions with your partner. 2 4 1. What is the function of an electrical machine? Tell the class the types of electrical machines and their applications that you know. 2. How do you define electrical equipment? List some cases of the use of electrical equipment in our daily life. 电气工程英语 Electrical machines, transformers, and daily life 1 An electrical machine is a device that can convert either mechanical energy to electrical energy or electrical energy to mechanical energy. When such a device is used to convert mechanical energy to electrical energy, it is called a generator. When it converts electrical energy to mechanical energy, it is called a motor. Since any given electrical machine can convert power in either direction , any mac ne can be used as either a generator or a motor. Almost all practical motors and generators convert energy from one form to another through the action of a magnetic field. The transformer is an electrical device that is closely related to electrical machines. Since transformers operate on the same principles as generators and motors, depending on the action of a magnetic field to accomplish the change in voltage level, they are usually stu ed together with generators and motors. These three types of electric devices are ubiquitous in modern daily life. Electric motors in the home run refrigerators , freezers, vacuum cleaners, blenders, air conditioners , fans, and many similar appliances . In the workplace , motors provide the motive power for