Calculating potential difference

[tmusgrove]

Homework Statement

In a 50 V circuit with a 400 Ohm resistance and a 600 Ohm resistance in series; Point A is between the two resistors and point B is to the right of the 600 Ohm resistor. Charge is moving from right to left.

Homework Equations

V=IR

The Attempt at a Solution

The answer is supposed to be 30 V, but why isn't it 50 V?

 

[ideasrule]

In parallel? It seems, from the rest of the question and the answer, like they're in series.

 

[tiny-tim]

Hi tmusgrove!

In a 50 V circuit with a 400 Ohm resistance and a 600 Ohm resistance in series; Point A is between the two resistors and point B is to the right of the 600 Ohm resistor. Charge is moving from right to left.
…
The answer is supposed to be 30 V, but why isn't it 50 V?

How can it be 50 V ?

That's the potential difference across both resistors.

 

[tmusgrove]

With TinyTim's reminder that the whole potential difference was 50, I could solve the problem. 600 Ohms and 400 Ohms = 1000 Ohms. 600 is 3/5 of 1000. 3/5 of 50 = 30. So, the answer is 30 V.

 

[tiny-tim]

Yup!