The Potential Difference between 2 points

[simion]

Homework Statement

What is the potential difference between points a and b in the diagram?
http://imgur.com/Ubr4A

Homework Equations

The Attempt at a Solution

I have calculated the currents to be:
I1=0.30A
I2=0.65A
I3=0.35A
What I tried doing was (0.30*5) - 0.35= 1.15 V but it's not right. Any help?

 

[azizlwl]

What is the value of V1?
http://img820.imageshack.us/img820/5158/cctb.jpg

 

[simion]

Sorry, it's 12.0 V

 

[gneill]

Homework Statement

What is the potential difference between points a and b in the diagram?
http://imgur.com/Ubr4A

Homework Equations

The Attempt at a Solution

I have calculated the currents to be:
I1=0.30A
I2=0.65A
I3=0.35A
What I tried doing was (0.30*5) - 0.35= 1.15 V but it's not right. Any help?

How did you arrive at that last expression? What does it represent?

 

[Nickie]

The potential difference between two points, in this case points a and b, is the difference in electrical potential energy per unit of charge between those two points. It is measured in volts (V). In order to calculate the potential difference between points a and b, we need to know the voltage drop across each resistor. Since the resistors are in series, the total voltage drop across the resistors will be equal to the voltage of the battery.

To calculate the potential difference between points a and b, we can use Ohm's Law, which states that V=IR, where V is the potential difference, I is the current, and R is the resistance. In this case, we have three resistors, each with different values, so we need to calculate the voltage drop across each one.

Using Ohm's Law, we can calculate the voltage drop across resistor R1 as V1=I1*R1=0.30*5=1.5V. Similarly, the voltage drop across resistor R2 is V2=I2*R2=0.65*5=3.25V, and the voltage drop across resistor R3 is V3=I3*R3=0.35*5=1.75V.

Since the resistors are in series, the total voltage drop across them will be equal to the voltage of the battery, which is 6V in this case. Therefore, the potential difference between points a and b is equal to the sum of the voltage drops across the resistors, which is 6V.

In summary, the potential difference between points a and b is 6V. It is important to note that this value may change depending on the values of the resistors and the voltage of the battery.