Current through a voltmeter with internal resistance

[jumbogala]

Homework Statement

You have a power supply of 10 V. It is connected in series to a 2 ohm resistor and a 5 ohm resistor.

You take the voltage across the 5 ohm resistor with a voltmeter that has an internal resistance of 3 ohms. What is the current through the voltmeter?

Homework Equations

The Attempt at a Solution

So I figured out the equivalent resistance of 5 ohms and 3 ohms is 1.815 ohms. Then the voltage across that is 4.83 V, which is the voltage read by the voltmeter.

Is the current going through the voltmeter just the same as the current going through the entire circuit? (So 10/(2 + 1.815))

Or is it the current just through the voltmeter's 3 ohm internal resistance? (Which I found to be 1.64 A)?

 

[rl.bhat]

Equivalent resistance R = 5*3/8 = ? Check this calculation.

 

[kerimek]

The current through the voltmeter is the same as the current through the entire circuit. This is because the voltmeter is connected in series with the resistors, so the current flowing through the circuit must also flow through the voltmeter. Therefore, the current through the voltmeter is 10/(2+5+3) = 1.11 A. The 3 ohm internal resistance of the voltmeter does not affect the current flow, as it is in series with the 5 ohm resistor and thus does not change the overall equivalent resistance of the circuit.