Solenoid experiment focused on: experiment to convert electrical energy into the class of the field ringtones, nobody hand bell ringing knock how will it? Perhaps some students know because solenoid, solenoid but also how to make the bell sound of it? Let us pass every day on campus students are listening too experiments to understand the electromagnet works. Purpose: 1. 2. Learn how to make nail electromagnet electromagnet structure and application in real life. Experimental Cognition: electromagnet works: simply summarized that the magnetic effect of current. When the coil is energized, the internal core is a magnetic field through the conduit. Core magnetized has become a magnet, so that due to the superposition of two magnetic fields to each other, so that the magnetic wire tube is greatly enhanced. Electromagnet core and the armature is magnetized to become two magnets of opposite polarity, generating electromagnetic attraction between them. Electromagnet is the use of carrier core coil electromagnetic suction to manipulate mechanical devices, electrical appliances expected to complete an action. Experimental Procedure: 1. Prepare understanding experiment experimental equipment: compass battery box, wire, nails, small pieces of iron, wires, switches, sandpaper 2. enameled stroke straight, two surface with sandpaper to sand off the paint (or can not conductive). 3. wear a good enameled wire around the nail leaving two wiring - coil 4. Place one end of the battery compartment and an enameled wire coil connector and the other end connected to the switch, and then switch to another thread and coil connections, circuit connection is completed, the final 5. Replace the battery in one hand and a nail is not wrapped around the wire in one hand and hold the power switch is turned on, the move to put the nail in place with a small piece of iron, and see whether we can suck up small iron plates . 6. Experiment 5 the same as the nail near the compass to move or shake nails and see what happens compass. Experiments Summary: electromagnet is core and coil. Only when the solenoid is energized a magnetic, cut off the current after the electromagnet is not magnetic; electromagnet magnetic strength can be changed by current strength and the number of coils (turns), turns long magnetic increases, the current increases large magnetic increases, decreases and vice versa. Electromagnet is also divided the Arctic and Antarctic; electromagnet poles can be changed; the ends of the wire connected to the battery positive and negative changes, the pole will change; electromagnet coil winding direction changes, the pole will change . Tip: This is similar to the experimental circuit shorted, hand can not touch the head, so as not to burn, not long power, so as not to run out of power quickly. Knowledge Development: electromagnet magnetic field direction is given amps can be used to determine, given the amp is set between the excitation current and the current direction of the magnetic field of the magnetic induction line relationship is also called the right-hand screw rule. (1) powered straight wire rule ampere (amp rule a): with the right hand holding the straight wire is energized, so that the thumb pointing direction of the current, four fingers point to energize the direction of magnetic field lines around a straight wire. (2) Solenoid rule of ampere (amp rule II): with the right hand holding the solenoid is energized, so that four fingers bent consistent with the current direction, so that the end of the thumb is referring to energize the solenoid N pole. Electromagnet has many advantages: the presence of a magnetic solenoid can be turned on and off current control; the size of the magnetic currents can be strong or weak or coil turns to control; control current resistance can also be changed to control the size of the magnetic size; it The pole can be controlled by changing the direction of the current, and the like. Namely: strength of the magnetic can be changed, presence or absence of magnetism can be controlled, the direction of the magnetic pole can be changed, may be due to magnetic currents vanishes. You know electromagnets used in life it? Maglev generator 2. 3. 4. Motor 5. bell automatic control device. Experiment: the experimental circuit diagram above describe. http://www.bjxwt.com Beijing precedent http://www.bjxwt.com.cn Beijing Education Development Co., Ltd. stationery small child playing precedent http://www.xianhe-edu.com Beijing Education Development Co. Company Stationery Factory