Which of the following circuits shows the correct connection of a voltmeter and an ammeter to measure the voltage v across resistor r and the current i going through r?

General
1

which of the following circuits shows the correct connection of a voltmeter and an ammeter to measure the voltage v across resistor r and the current i going through r?

2

To measure the voltage across resistor r (v) and the current going through resistor r (i), the correct connection of a voltmeter and an ammeter would be as follows:

  1. Connect the voltmeter in parallel across resistor r: The positive terminal of the voltmeter should be connected to the point on the circuit where the voltage measurement is desired (across resistor r), and the negative terminal should be connected to the reference point (usually the ground or the negative terminal of the power supply).

  2. Connect the ammeter in series with resistor r: The ammeter should be placed in series with resistor r, meaning that the current flowing through the circuit will also flow through the ammeter. The positive terminal of the ammeter should be connected to the side of resistor r where the current enters, and the negative terminal should be connected to the side where the current exits.

By following these connections, the voltmeter will measure the voltage drop across resistor r, and the ammeter will measure the current flowing through resistor r.

It is important to note that when measuring voltage with a voltmeter, the voltmeter should have a very high input impedance so as not to affect the circuit being measured. Likewise, when measuring current with an ammeter, the ammeter should have a very low resistance so as not to disturb the current flow in the circuit.

Please keep in mind that without any specific circuit diagrams or options provided, I can only provide a general explanation of the correct connection of a voltmeter and an ammeter for measuring voltage and current across a resistor.