# I don't get ammeters or voltameters!

Hello everyone, so far i've missed every single problem, this book has a section on ammeters and voltameters that is like 1 paragraph long and just says, the ammeter measures current, the voltameter measures Potential difference. And this problem asks:
n Fig. 28-40, the ammeter and voltmeter resistances are 2.00 and 268 , respectively. Take E= 12.0 V for the ideal battery and R0 = 119 .
Here is my work: http://img201.imageshack.us/img201/2220/pink8iw.jpg [Broken]

Figure 28-40a Figure 28-40b
Here is the first figure, 28-40a: http://www.webassign.net/hrw/28-40a.gif

(a) If R = 93.0 what will the meters read for the two different connections (Figs. 28-40a and b)?
Figure A:

Current wrong check mark A
Potential Difference V

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Chi Meson
Homework Helper
The current through R is not the same as the current through Ro. Are you supposed to use the loop rule to solve this? I'd think it'd be easier to do simple parallel/series analysis:

Resistor R is in paralle with the voltmeter. This parallel is in series with the ammeter and Ro. Find the total current and then the voltage drop across the parallel.

thanks!! he never said how i have to solve it...So u said to find the total current, then the voltage drop, Do i use the formula for adding up resistors in paralell? like I know the same potienal differences across all resistors in parellel, so 1/Req = 1/Ro + 1/Rvoltmeter;
then find Req = Ro + Rammeter ?

Chi Meson