# Circuitry theory analysis

1. Nov 15, 2006

### nontypicalazn

hi, im wondering if anyone can answer this question of the following circuit setup, thanks:

an AC source connected parallel to a volt meter, together in series with an ampmeter, then series with some sort of device. No numbers are given. Volt and Amp meters are both ideal. What is the power delivered to (across, dissipated by, would there be any difference) unknown device, relative to Irms * Vrms.
thank you.

http://img215.imageshack.us/img215/9852/untitledml4.jpg

thanks

Last edited: Nov 16, 2006
2. Nov 16, 2006

### marcusl

You already gave the answer, P = Irms * Vrms. Power is delivered to or dissipated by the device (not "across").

3. Nov 16, 2006

### OlderDan

I'm not sure what the point of your question is. There is a concept of "apparent power" that can be measured with your rms meters, but that may not be telling you the true power delivered to the load. If the load is purely reactive, no power is actually delivered.

Here is a rather clear discussion of the problem.

http://www.ibiblio.org/obp/electricCircuits/AC/AC_11.html

4. Nov 16, 2006

### nontypicalazn

well, thats what im kinda asking. This unknown device is not defined. but generally speaking, what is the power dissipated by the load?
is it equal to IV
less than IV
or possibly equal to IV even when capacitors and inductors are present?

5. Nov 16, 2006