When the voltmeter is paralleled in the circuit under test, what are the consequences of open circuit and short circuit of the voltmeter to the circuit? Forget to say, what if the voltmeter is in series? There are two consequences

When the voltmeter is paralleled in the circuit under test, what are the consequences of open circuit and short circuit of the voltmeter to the circuit? Forget to say, what if the voltmeter is in series? There are two consequences

Parallel connection: the open circuit does not affect the circuit, and the short circuit will short the circuit under test
Series connection: the open circuit will break the whole line, and the short circuit will not affect the circuit

Does the voltmeter show the number after the power supply is short circuited?
As shown in the figure

No, because after the short circuit of the power supply, all the current flows directly to the negative pole through the wire, and there is almost no current passing through both ends of the bulb, which can be regarded as an open circuit. The voltmeter is equivalent to connecting to both ends of the wire, and what it measures is the voltage value of the wire. Because the resistance of the wire can be ignored, the voltmeter has no indication

When the voltmeter is connected in parallel with the power supply and another user, and the user connected in parallel with the voltmeter has a short circuit, please explain whether the voltage indication becomes larger or smaller

The reading of voltmeter will decrease. 1. The voltmeter is usually connected in parallel with the power supply or the power supply end of the electrical appliance. 2. When the electrical appliance connected in parallel with the power supply is short circuited, if the power supply is small, the power supply voltage will decrease and the reading of the ammeter will decrease. 3. If the electrical appliance has a fuse or short-circuit safety switch and is effective, when the electrical appliance is short circuited, the fuse will

There is an ammeter in parallel in the circuit, which causes short circuit of the power supply, but there is a voltmeter on the main road. The indication of the two meters is specific
I know the voltmeter should have indication. But it's power short circuit and voltmeter. I don't know the specific situation of the ammeter. Please be more careful

Junior high school stage: the number of voltage is power supply voltage, and the number of current is zero
High school stage: the voltage indication is slightly smaller than the power supply voltage, and the current indication is close to zero