Voltmeter reading between point b and ground with 5×10^4 Ω resistance

[joshanders_84]

This is another problem I am having troubles with. Here's the prompt:

What is the reading of a voltmeter with the proper range and with resistance 5*10^4 Ohms when connected between point b and ground?

I know that for voltmeters, V = I_fs (R_c + R_s), and I tried solving for V using the I through the system as I_fs, which I solved as (400V/300000) = .001333, and then using 5*10^4 and 200000 as the resistors, but it says my answer is off by an additive constant. I don't understand what I am dong wrong...all help is appreciated. Thanks
Josh

 

[ceptimus]

If the voltmeter wasn't there, or was perfect, then the voltage at b would be 2/3 of that at a.

Now when the voltmeter is present, its resistance is in parallel with the 200k-ohm resistor, so you can calculate the equivalent resistance of the parallel combination, and get a new ratio for the voltages at a and b.

 

[joshanders_84]

I don't understand how that helps...sorry. I just don't get what I am doing wrong still, or how the above would help me go further...

 

[joshanders_84]

o i ci I got it now, thank you