A good ammeter has low resistance to ensure it does not significantly affect the current flowing through the circuit it is measuring. In contrast, a good voltmeter has high resistance to minimize the current drawn from the circuit, allowing it to measure the voltage across a component without altering its behavior. This difference in resistance characteristics is crucial for accurate measurements in electrical circuits.
Aim of any measuring instrument is to measure the object without affecting it. Voltmeter is used to measure voltage between two points and connected in parallel. Thus voltmeter should not change the voltage. If voltmeter resistance is very high, it will be as good as infinity compared to load. Thus connecting voltmeter will not change the voltage and measure it accurately.
For an 8 ohm speaker, 8 ohms is perfect. "Good" and "bad" are relative to the application.
If all you have is a voltmeter, then resistance can only be calculated. If you know the total volts applied and current, either total current if in series ckt or current through the component if parallel type ckt, then the following formulas apply: R=Eapp÷It (series ckt) R=Eapp÷IR (parallel ckt)
It is called resistance Good conductors have a bad resistance While bad conductors or insulators have good resistance against the flow of electricity
When considering electricity, Current (measured in Amps) is often considered the flow of energy. The force behind the flow is the Volts. While the volts can be measured between any two points in the circuit (open, or closed), measuring the current, or flow of energy typically requires interrupting the flow. Somewhat like water. One can measure pressure of the water on a branch, but one must have a way to monitor the actual flow to determine how much water has passed. There are "exceptions" though. If you have an AC circuit, then an inductive ammeter can measure the amps around a single leg if the circuit without being installed inline with the circuit. Even with a DC circuit, it may be desirable to design a bypass or shunt circuit so that the majority of the current bypasses the ammeter, and only a small amount of the current actually flows through the ammeter.
An ammeter has a finite resistance which is inserted in series with the rest of the circuit, increasing the total resistance and decreasing the current. A good ammeter has a very low resistance, so it shouldn't affect the circuit noticeably.
Because its function is to measure the current, i.e. the amount of electrical flow in the circuit, and this require that the current flows through the ammeter A good ammeter has very low series resistance, so connecting it in series will not affect your circuit. Be careful when using an ammeter , because of its very low resistance , it can cause a short circuit if you use it by mistake to measure "voltage", so avoid connecting it in Parallel.
Aim of any measuring instrument is to measure the object without affecting it. Voltmeter is used to measure voltage between two points and connected in parallel. Thus voltmeter should not change the voltage. If voltmeter resistance is very high, it will be as good as infinity compared to load. Thus connecting voltmeter will not change the voltage and measure it accurately.
For an 8 ohm speaker, 8 ohms is perfect. "Good" and "bad" are relative to the application.
the voltmeter use a SLR camera because this is the latest camera and the good light and good shot of a picture
Of course. A good voltmeter can be applied across anything, since its impedance is high and its presence has no effect on the operation of the circuit. When it's connected across a variable resistor, the voltmeter most likely reveals a changing voltage as the resistor is varied.
If all you have is a voltmeter, then resistance can only be calculated. If you know the total volts applied and current, either total current if in series ckt or current through the component if parallel type ckt, then the following formulas apply: R=Eapp÷It (series ckt) R=Eapp÷IR (parallel ckt)
A voltmeter uses the principle of Ohm's law, which states simply that the amount of current that flows in a circuit is equal to the voltage applied divided by the resistance of the circuit. Therefore, if one were to connect a known resistance in series with a meter across a voltage source, then the meter deflection would be proportional to the current flow and hence the voltage. The meter is calibrated in volts so that the test voltage can be read directly. The meter used in a voltmeter is very sensitive, typically 50 micro-amperes so that it does not affect the reading by its load on the circuit. pizza is good when volts don't go thru!!
Good conductor = low resistance.
A milliammeter is a sensitive instrument placed in series in a circuit and is calibrated to measures current going through it, and therefore the whole circuit, without presenting enough resistance to affect the current going through it or reducing the voltage available to the rest of the circuit. A voltmeter is a milliammeter used in parallel to the circuit. Since the milliammete has very little resistance, if it is used this way it will present as a short to the rest if the circuit, not give a valid reading, and probably burn out. To use a milliammeter as a voltmeter, a significantly large resistance needs to be placed in series with the milliammeter. If the resistance is large enough, but not too large, it will prevent the meter from being a short, not affect the circuit load but still allow enough current to go through the meter to get a reading. If you want to measure AC (alternating current) you will also have to include a rectifier circuit. To be useful as a voltmeter, the meter will need to be calibrated, a tedious job since the meter responses probably are not linear. Modern multimeters are available that will act as a voltmeter with several range setting. You can get them at any electronic or tool store such as Sears, Harbor Freight, or Radio Shack. Even the cheap 10 dollar ones will do a good job for most purposes although professional models that do so much more and with greater precision can be really expensive.
No, a good conductor has a low resistance.
good.