Capacitance equired to store an energy of

In summary, the conversation discusses the calculation of capacitance required to store 8 kWh of energy at a potential difference of 600 V. The formula P = U/t and U = 1/2CV^2 are mentioned, and the conversion of 8 kWh to 28800 kWs is shown. The correct formula C = (2U)/V^2 is used, but initially leads to the wrong answer. The conversion of 1 kWh to 3.6 x 10^6 J is also mentioned. Ultimately, the correct answer is found by converting the value of 8 kWh to 28800 J and using the formula C = (2U)/V^2.
  • #1
mr_coffee
1,629
1
Hello everyone. The question is:
What capacitance is required to store an energy of 8 kWh at a potential difference of 600 V?
\This seems like a simple problem..our professor hasn't went over this yet but i saw in the book. P = U/t; I also saw; U = 1/2CV^2; So they gave me U right? because P = U/t, so U = 8 kWh, i converted this into 8kWsecond, by doing this:
8kwh x 3600sec = 28800kws; I then used:
C = (2U)/v^2; C = [2*28800]/(600)^2 = .16 which was wrong, i also tried just using 8, and 8/3600, all didn't work.
 
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  • #2
1 KWH = 1*1000*3600 J = 3.6 x 10^6 J (S.I. Unit of energy)
 
  • #3
mr_coffee said:
8kwh x 3600sec = 28800kws;

There is still the KILO in there, which you should convert numerically (hint: 1000:-)
 
  • #4
Ahhh thank you guys, worked great :)
 

1. What is capacitance and how does it relate to energy storage?

Capacitance is a measure of an object's ability to store an electrical charge. It is represented by the letter C and is measured in units called farads. The higher the capacitance, the more charge an object can hold. In terms of energy storage, capacitance is directly proportional to the amount of energy that can be stored. This means that a higher capacitance value results in a greater amount of energy being stored.

2. How is capacitance calculated?

The capacitance of an object is calculated by dividing the amount of charge (Q) stored on the object by the potential difference (V) across the object. In equation form, this is expressed as C = Q/V. It is important to note that capacitance is also affected by the physical characteristics of the object, such as its size and shape.

3. What is the relationship between capacitance and voltage?

Capacitance and voltage have an inverse relationship. This means that as voltage increases, capacitance decreases and vice versa. This is because as the potential difference increases, the object becomes more "charged" and has a greater ability to store energy. On the other hand, a decrease in voltage results in a decrease in the object's ability to store energy.

4. How does the material of an object affect its capacitance?

The material of an object has a significant impact on its capacitance. Materials with a higher dielectric constant, such as ceramics or polymers, have a higher capacitance compared to materials with a lower dielectric constant, such as air or vacuum. This is because the dielectric constant determines the object's ability to store charge and therefore affects its capacitance.

5. What are some real-world applications of capacitance for energy storage?

Capacitors, which are devices that use capacitance to store energy, have a wide range of applications in various industries. They are commonly used in electronic circuits to store energy and regulate voltage. Capacitors are also used in power grids to store energy and improve power quality. In addition, they are used in renewable energy systems, such as solar panels and wind turbines, to store energy generated from these sources.

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