# Energy Stored in a Capacitor

• hellogirl88
In summary, a capacitor is an electronic component that stores electrical energy in an electric field. It consists of two conductive plates separated by an insulating material called a dielectric. When a voltage is applied, an electric field is created and the energy is stored in this field. The unit of measurement for energy stored in a capacitor is the joule (J), and it can be calculated using the formula E = 1/2CV^2. The amount of energy stored is affected by the capacitance, voltage, and type of dielectric material used.

#### hellogirl88

A capacitor is completely charged with 650 nC by a voltage source that had 375 V.

The initial air gap of the capacitor above was 7 mm. What is the stored energy if the air gap is now 11 mm?

Has the voltage source been disconnected before increasing the distance?

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

In this scenario, the capacitor is initially charged with 650 nC by a voltage source of 375 V. The initial air gap is 7 mm, but it is now 11 mm. To calculate the stored energy, we first need to determine the capacitance of the capacitor. This can be done using the equation C = Q/V, where Q is the charge and V is the voltage. In this case, the capacitance would be 650 nC/375 V = 1.73 nF.

Now, using the equation E = 1/2 * C * V^2, we can calculate the stored energy with the new air gap of 11 mm. Plugging in the values, we get:

E = 1/2 * (1.73 nF) * (375 V)^2 = 153.4 nJ

Therefore, the stored energy in the capacitor is 153.4 nJ when the air gap is 11 mm. This is an increase from the initial stored energy of the capacitor when the air gap was 7 mm. This is because the capacitance decreases as the air gap increases, resulting in a higher stored energy.

## 1. What is a capacitor?

A capacitor is an electronic component that stores electrical energy in an electric field. It consists of two conductive plates separated by an insulating material called a dielectric.

## 2. How does a capacitor store energy?

When a voltage is applied to a capacitor, an electric field is created between the two plates. This causes positive charges to accumulate on one plate and negative charges on the other. The energy is stored in this electric field.

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

The unit of measurement for energy stored in a capacitor is the joule (J). However, it is more commonly measured in microjoules (μJ) or millijoules (mJ) in electronic circuits.

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

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

## 5. What factors affect the amount of energy stored in a capacitor?

The amount of energy stored in a capacitor is affected by its capacitance, the voltage applied to it, and the type of dielectric material used. Capacitors with larger capacitance values and higher voltages can store more energy, and certain dielectric materials have higher energy storage capabilities than others.