There is a power supply resistance switch in the circuit. When the voltmeter is in series in the circuit and the ammeter is in parallel in the circuit, the consequence is that both the ammeter and the voltmeter are There is a power resistance switch in the circuit. When the voltmeter is connected in series and the ammeter is connected in parallel, the result is a. the ammeter and the voltmeter are damaged. B. the ammeter is damaged, and the voltage representation is zero. C. The current representation is unchanged, and the voltage representation is reduced. D. the current representation is reduced, and the voltage representation is reduced

There is a power supply resistance switch in the circuit. When the voltmeter is in series in the circuit and the ammeter is in parallel in the circuit, the consequence is that both the ammeter and the voltmeter are There is a power resistance switch in the circuit. When the voltmeter is connected in series and the ammeter is connected in parallel, the result is a. the ammeter and the voltmeter are damaged. B. the ammeter is damaged, and the voltage representation is zero. C. The current representation is unchanged, and the voltage representation is reduced. D. the current representation is reduced, and the voltage representation is reduced

The resistance of the ammeter is very small, which is equivalent to a short circuit. The internal resistance of the voltmeter is very large, which is equivalent to an open circuit. Therefore, the voltmeter is opened by the ammeter, and the voltmeter has no indication. The hesitation of the second ammeter is equivalent to a wire, so the current is very large and it will be damaged

How to choose a voltmeter for measuring resistance by voltammetry?

If it is a test, the standard answer given by our teacher is:
1. Because this is a group of measuring points, you will usually be given a rated voltage value. You can choose the appropriate range according to this voltage value (of course, the sliding rheostat should be adjusted to the maximum value) or try to touch the ammeter first (that is, first use a large range, if it does not exceed 0.6A, then use a small range)
2. If you are not given a suitable voltage value, the power supply voltage used by students or laboratories to measure the resistance by the desk method will not be too large. You can still use a small range (voltmeter), and you can use a sliding rheostat to protect the circuit. However, in order to conduct a rigorous test, you should also try to touch the voltmeter and the ammeter
In addition, if it's a test question, don't forget to measure it many times to get the average value

In the selection of power supply voltage and range of ammeter and voltmeter, this test and resistance measurement experiment follow the same principles
In the selection of power supply voltage and range of ammeter and voltmeter, this test and resistance measurement experiment follow the same principles__________________ The differences are_____________________ .

Both voltmeter and ammeter have the problem of measuring range, that is, the selected range should be greater than the measured range. The difference is that the voltmeter is connected in parallel with the measured object, while the ammeter is connected in series with the measured line

In the experiment of measuring resistance by volt ampere method, if the power supply voltage is 3 V and the measured resistance is 20 Ω, the range of voltmeter and ammeter should be selected as "0"?

The range of the voltmeter depends on the power supply voltage 3V, and the voltmeter uses 0 -- 3V
The current is 0.15A for 3 / 20, and the current meter is 0-0.6a