How Do You Calculate Power and Resistance in Electrical Circuits?

[Imposta]

I need help with these 2 problems:

1. If Rx = 8, compute (a) I (b)Vx (c) the power absorbed by the voltage source (d) the power supplied by Rx.

2. Determine the value of Req

 

[vk6kro]

There are problems with the first question.

Resistors absorb power and voltage sources supply power. Not the other way around.

In the first diagram there is a short circuit across the 4 ohm resistor. This makes 5 components irrelevant.

Assume this short circuit is not intended and remove it.

After that, the exercise is just an example of solving the result of serial and parallel resistor combinations.

The rules of this Forum are that you need to show your own effort at solving these problems and that you have found the necessary formulas for working out resistor combinations.
It would actually be easier to just tell you the answers, but you wouldn't learn anything if that happened. So, it isn't going to happen. :)