What is the value of resistance for an ideal voltmeter

\( \newcommand\) • • • • • • • • • • • learning objectives • Compare circuit connection of an ammeter and a voltmeter Voltmeters and ammeters measure the voltage and current, respectively, of a circuit. Some meters in automobile dashboards, digital cameras, cell phones, and tuner-amplifiers are voltmeters or ammeters. Voltmeters and Ammeters: A brief introduction to voltmeters and ammeters for introductory physics students. Voltmeters A voltmeter is an instrument that measures the difference in electrical potential between two points in an electric circuit. An analog voltmeter moves a pointer across a scale in proportion to the circuit’s voltage; a digital voltmeter provides a numerical display. Any measurement that can be converted to voltage can be displayed on a meter that is properly calibrated; such measurements include pressure, temperature, and flow. Voltmeter: Demonstration voltmeter from a physics class In order for a voltmeter to measure a device’s voltage, it must be connected in parallel to that device. This is necessary because objects in parallel experience the same potential difference. Voltmeter in Parallel: (a) To measure the potential difference in this series circuit, the voltmeter (V) is placed in parallel with the voltage source or either of the resistors. Note that terminal voltage is measured between points a and b. It is not possible to connect the voltmeter directly across the EMF without including its internal resistance, r. (b) A digital voltmete...

- Hint: An ideal voltmeter should have no current passing through it. An ideal ammeter should let the entire current pass without any hindrance. And we know current is inversely proportional to resistance, that means the more the resistance less current passes through it and vise versa. Complete step-by-step solution - A voltmeter is connected in parallel to the current carry wire, to measure the potential difference between two points. Since it is connected to the wire, a finite amount of current will pass through it. This will lead to the change in actual flow of current, and hence, change in the actual potential difference. In order to minimize this, the resistance to a voltmeter is kept high enough such that the current passing through it is minimum. However, this would still cause some imperfections in the reading. In an ideal situation, where the voltmeter is able to measure the actual potential difference across two points, there should be no current passing through it, and hence its resistance should be infinite. An ammeter is connected in series with a current carrying wire, to measure current passing through it. Since it is connected to the wire and has a finite amount of resistance, there will be some potential difference across it. This will lead to the change in actual flow of current. In order to minimize this, the resistance to an ammeter is kept minimum such that the voltage drop across it is minimum. However, this would still cause some imperfections in th...

For the sake of expirementing, as far as I have tested (with simulators online) connecting an ohmmeter in parallel with the single component in a closed circuit with a generator short circuits, concluding that the resistance of an ohmmeter is ideally 0, right? I have found no conformation nor information about this online, but what made me wonder even more is an ohmmeter acts as a voltmeter that exports power, and voltmeters having ideally $\infty$ power, so an ohmmeter having no resistance didn't make much sense, perhaps because it is the source of the energy it does not require resistance? Current leaves and enters through it, doesn't pass through it. I have absolutely no idea how resistance works with components producing energy so bare with me here! Like, does a generator have resistance as well (well a simple google search says yes), and why? No electricity goes through it I think. And perhaps ultimately an ohmmeter and a generator don't relate in terms of resistance, sharing the common aspect of producing energy doesn't affect that. $\begingroup$ I don't think it's obvious what "ideal" means for an Ohm meter, but I'm pretty sure that your average, bench-top Ohm meter (a) is only intended to measure the resistance of a component that has been isolated from any circuit, and (b) delivers power to the the component when it is being used as intended. $\endgroup$ An ohmmeter is • supplying power to a circuit and • comparing the voltage across two legs of the circuit (a ref...

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• Voltmeter: A voltmeter would be an instrument as well as a gadget that measures the voltage or potential difference throughout the endpoints or the terminals of a wire as well as an electrical device. • Whenever they connect the voltmeter device in parallel, the resistance should always be equivalent to infinity. As we are not changing this same voltage or current throughout the existing circuit • Hence high resistance will lead to no current • The current flow for such a perfect (ideal) voltmeter would be zero. Therefore, the resistance of an ideal voltmeter will be infinite.

(I'm a student just like you so I might not be right) From what Sal said in an earlier video, the flow of electrons in a circuit is probabilistic. And current is the measure of how many electrons (charge) flows through a point per unit time (seconds). a path with high resistance would make the current flow through it much slower than a path with no resistance. So the current is lower for a high resistor because it lets fewer charge through it per second, not because the electrons intuitively "know" which path has least resistance. Electrons will go through every path, but lower resistance means some paths will let electrons through at a higher rate and therefore have a higher current Ah, but think about what would happen if this was true. If there are more electrons flowing into the resistor than flowing out of it (flowing electrons being what current is), then there would have to be a growing pile of electrons forming in the resistor. Since electrons are negatively charged and repel each other, this pile of electrons would quickly form a voltage greater than the one driving the current and stop it, or if the driving current was strong enough, cause the resistor to shoot out lightning. We don't see this, so we conclude that the current is the same before and after the resistor. This is one half of Kirchhoff's rules, which you can read about here for example: Hello Anusha, Before I answer your question consider the attributes of an ideal voltmeter and an ideal ammeter: The ...

Consider an analog voltmeter. I understand that the internal resistance of the voltmeter should be high enough to not lower the actual voltage across the load connected to the voltmeter, but, at the same time, if the resistance was infinite, there will be no current flowing through the voltmeter which means no magnetic field will be produced and the pointer wouldn't deflect. \$\begingroup\$ @ilkkachu so what I should understand by the word 'ideal' in the context of this analog voltmeter is that (ideally) no current is supposed to flow through the voltmeter and, consequently, there's no voltage drop across the load, but in real life current has to flow into the voltmeter so there must be a voltage drop; however, designers try their best to minimize the amount of current flowing through the voltmeter by choosing the appropriate resistance. Am I correct? \$\endgroup\$ Your reasoning is correct if you take “voltmeter” to mean imagine taking that measurement without disturbing the circuit. The whole idea of an ideal instrument of any sort is to ignore the limitations of a physical implementation of the concept; there does not have to be a possible way to do it. That said, there are ways to measure DC voltage with a nearly infinite input impedance. • The The electrostatic voltmeter electrically resembles a capacitor, so its input impedance is infinite at DC (if you ignore leakage across insulators). If you remove it from a circuit, the needle will keep its reading unless you sho...