# Using a voltmeter

## Homework Statement

A circuit consists of a series combination of 6.00 -kOhm and 4.50 kOhm resistors connected across a 50.0-V battery having negligible internal resistance. You want to measure the true potential difference (that is, the potential difference without the meter present) across the 4.50 -kOhm resistor using a voltmeter having an internal resistance of 10.0 kOhm.

What potential difference does the voltmeter measure across the 4.50 -kOhm resistor?

## The Attempt at a Solution

I tried doing (50*10000)/V - 10,000 = 4500 and solving for V but I got 35.5 and this isn't the right answer. There are no formulas in my book for calculations with voltmeters I got this formula online so I'm not even sure if it is correct can anyone help me out?

alphysicist
Homework Helper
Hi physstudent1,

## Homework Statement

A circuit consists of a series combination of 6.00 -kOhm and 4.50 kOhm resistors connected across a 50.0-V battery having negligible internal resistance. You want to measure the true potential difference (that is, the potential difference without the meter present) across the 4.50 -kOhm resistor using a voltmeter having an internal resistance of 10.0 kOhm.

What potential difference does the voltmeter measure across the 4.50 -kOhm resistor?

## The Attempt at a Solution

I tried doing (50*10000)/V - 10,000 = 4500 and solving for V but I got 35.5 and this isn't the right answer. There are no formulas in my book for calculations with voltmeters I got this formula online so I'm not even sure if it is correct can anyone help me out?

Treat the voltmeter as just a resistor being hooked in parallel to the 4.5 kOhm resistor. In this new circuit, what is the potential difference across the 4.5 kOhm resistor?