What is the potential difference between the plates?

In summary, the conversation revolves around a problem with a parallel-plate air capacitor with a capacitance of 730 picoFarads and a charge of 2.95 microCoulombs on each plate. The main question is how to find the potential difference between the plates, with one person suggesting using the equation V=Q/C. However, a mistake was made in the calculation and the correct result is actually 4041.1 V. The conversation then moves on to discussing tripling the distance between the plates, which would result in a potential difference of 3V or 12123.3 V. The equation U=1/2 Q V is then mentioned as a way to calculate the work required to triple the separation
  • #1
eku_girl83
89
0
Here's my problem:
A parallel-plate air capacitor has a capacitance of 730 picoFarads. The charge on each plate is 2.95 microCoulombs.
a) What is the potential difference between the plates? I used the equation V=Q/C to get 2.4746E-4 V, but this is incorrect.
b)If the charge is kept constant, what will be the potential difference between the plates if the separation is tripled?
I think it would be divided by three.
c) How much work is required to triple the separation?
U=1/2 Q V

I think if I could calculate the potential difference correctly, I could work the rest of the problem. Any hints/help would be welcome!
 
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  • #2
Check your arithmetic, I do not get the result you posted using the same equation and numbers. Post your calculation.
 
  • #3
I punched the numbers into the calculator wrong! I now get the voltage equal to 4041.1
Tripling the distance produces a voltage of 3V or 12123.3
Now, how do I apply the equation U=1/2 Q V to find the work required to triple the separation?
 
  • #4
it would be Uf-Ui=W
 
  • #5
Thank you! You are all so helpful :)
 

1. What is potential difference?

Potential difference, also known as voltage, is the difference in electric potential energy per unit charge between two points in an electrical circuit. It is measured in volts (V).

2. How is potential difference related to electric current?

Potential difference is the driving force for electric current, meaning that it is the reason why electrons flow from one point to another in an electrical circuit. The greater the potential difference, the greater the electric current.

3. What causes potential difference between two points?

Potential difference is caused by the separation of electrical charges. This can be achieved by using a battery, which creates a potential difference between its positive and negative terminals, or by using a power source such as a generator.

4. Can potential difference be negative?

Yes, potential difference can be negative. This means that the direction of electron flow is opposite to the conventional current flow. In other words, the electrons are moving from the point with lower potential to the point with higher potential.

5. How is potential difference measured?

Potential difference is measured using a voltmeter, which is a device specifically designed to measure voltage. The voltmeter is connected in parallel to the two points for which the potential difference is being measured, and the reading is given in volts.

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