What is the energy stored in the capacitor?

Check the question. I think it should be 20 volts not 20 J.In summary, the conversation discusses placing 20 J across a 15uF capacitor and calculating the energy stored in the capacitor. The correct unit should be 20 volts, not 20 J. The energy stored in a capacitor is calculated using the relationship between voltage and charge and integrating with respect to voltage.
  • #1
donjt81
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20 J is placed across a 15uF capacitor. What is the energy stored in the capacitor?

any ideas on how to do this?
 
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  • #2
donjt81 said:
20 J is placed across a 15uF capacitor. What is the energy stored in the capacitor?

any ideas on how to do this?
Check the question. I think it should be 20 volts not 20 J. (If 20 J is added to the capacitor, the energy stored in the capacitor is 20 J. because there is no energy is lost due to resistance).

The energy is [itex]\int_0^q Vdq[/itex] where V = potential (energy/charge) between the plates of the capacitor. It is 0 Volts initially but increases to 20 V. when fully charged.

Use the relationship between V and Q in a capacitor to express dq in terms of dV and then integrate with respect to V over the range 0 to 20 V.

AM
 
  • #3


The energy stored in a capacitor is given by the equation E = 1/2 * C * V^2, where C is the capacitance and V is the voltage across the capacitor. In this case, the voltage is given as 20 J and the capacitance is 15uF (or 15 x 10^-6 F). Plugging these values into the equation, we get E = 1/2 * 15 x 10^-6 F * (20 J)^2 = 6 x 10^-3 J. Therefore, the energy stored in the capacitor is 6 millijoules (mJ).
 

1. What is a capacitor?

A capacitor is an electronic component that stores electrical energy in an electric field. It is made up of two conductive plates separated by a non-conductive material, known as a dielectric.

2. How is energy stored in a capacitor?

When a capacitor is connected to a power source, such as a battery, one plate becomes positively charged and the other becomes negatively charged. This creates an electric field between the plates, which stores the energy in the form of potential energy.

3. What is the unit of measurement for energy stored in a capacitor?

The unit of measurement for energy stored in a capacitor is joules (J), which is the same unit used to measure energy in other forms, such as mechanical or thermal energy.

4. How is the amount of energy stored in a capacitor calculated?

The energy stored in a capacitor can be calculated using the formula E= 1/2 * C * V^2, where E is the energy in joules, C is the capacitance in farads, and V is the voltage in volts.

5. Can the energy stored in a capacitor be discharged?

Yes, the energy stored in a capacitor can be discharged by connecting the two plates together, allowing the electric charge to flow from one plate to the other. This discharge of energy is commonly used in electronic circuits to power devices or to control the flow of electricity.

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