Voltmeter is an instrument to measure voltage, common voltmeter - Voltmeter Symbol: V, the galvanometer which has a permanent magnet between the two current meter in series with a coil of wire terminals constituted coil is placed in a magnetic field of the permanent magnet and connected by a drive means and a table pointer. Most tables are divided into two voltage ranges. Voltmeter has three terminals, one negative terminal, two positive terminals, connect the positive and the positive voltmeter circuit, a negative electrode is connected to the circuit. Voltmeter must be connected in parallel with the measured electrical appliances. Voltmeter is a fairly large resistor, considered to be the ideal circuit. Junior commonly used laboratory voltmeter range is 0 ~ 3V and 0 ~ 15V. Voltmeter is an instrument to measure voltage, common voltmeter - symbol voltmeter is "V". Traditional analogue voltmeter comprises a galvanometer, the galvanometer which has a permanent magnet between the current meter in series with the two terminals of a coil constituted by a wire coil placed in the magnetic field of the permanent magnet, and is connected via a transmission table pointer. Most tables are divided into two voltage ranges. Voltmeter has three terminals, one negative terminal, two positive terminals, connect the positive and the positive voltmeter circuit, a negative electrode is connected to the circuit. Voltmeter is a big resistor, considered to be the ideal circuit. In parallel with a voltmeter (with the other appliances in parallel) in a parallel circuit and appliances, if no other electrical appliances in the trunk, you can think to measure the supply voltage (in parallel with the electrical circuit because all enjoyed the power supply voltage ); If the trunk is also connected to other appliances that will share this with the electrical parts of the supply voltage, the voltage meter can only be part of the voltage measurement (which is used in electrical connection with the electrical voltage which is). To know in the voltage meter, a magnet and a coil of wire through the current in the coil generates a magnetic field, rotates under the action of the magnet so that the coil is energized, which is the header portion ammeter, voltmeter. This current can pass through a small header ends can withstand voltage is small (certainly far less than 1V, may be zero zero a few volts or less), in order to measure the actual circuit voltage, you need to This voltage is in series with a relatively large sheet resistance, made of a voltmeter. Thus, even ends with a relatively large voltage, but most of the voltages are applied to the large increase in the resistance of the voltmeter will be very small head. The internal resistance of the voltmeter is a great instrument, the general should be more than a few thousand euro. It is the role of the head table with the energized conductor by the magnetic force of the magnetic field made of. Table inside a permanent magnet, the magnetic field generated between the poles, a coil spring at each end of the spring coil in a magnetic field, a spring terminal connection table for each, between the coil springs are connected by a shaft, the shaft is relatively ammeter on the front, there is a pointer. When a current is passed, the current along the spring, the shaft through a magnetic field, the magnetic induction current cut line, so the role of the magnetic field strength, deflection coil, drive shaft, pointer deflection. Since the magnetic force varies with the size of the current increases, thereby making it possible to observe the degree of deflection magnitude of the current through the pointer.