Why Does the Voltage at Point B Measure 30V?

[james11223]

Homework Statement

Show that the voltage drops over the circuit is 0. What is the voltage at B?

Homework Equations

I = E/Req

The Attempt at a Solution

120V/120ohms = 1 A

120V - (80*1) - (10*1)- (30*1) = 0

120 - 80 - 10 = 30V at B

I have nooo idea about the B part... can someone please verify!

THANKS!

 

[gneill]

You seem to have done all right.

The question is a bit sloppy though: they should have specified a point of reference when they asked about the voltage at node B. The default assumption in this case is to reference the "-" terminal of the supply.

 

[james11223]

So in my understanding the current is flowing clockwise... is that a correct assumption?

 

[gneill]

So in my understanding the current is flowing clockwise... is that a correct assumption?

The battery symbol in the schematic implies that it is "+" on top, so yes, conventional current flow would be clockwise in the circuit.