91Ó°ÊÓ

Capacitors are essential components for energy storage in electronic circuits. They temporarily hold electric charge, storing energy for various applications.
When a capacitor is charged, it accumulates energy in an electric field between its plates. The amount of energy stored is determined by its capacitance and the voltage across it. This makes capacitors crucial for devices like cardiac defibrillators, where rapid energy discharge is needed.
The stored energy (E) in a capacitor is calculated using the formula: \( E = \frac{1}{2} C V^2 \). Here, \( C \) represents capacitance and \( V \) is voltage.
This equation illustrates how energy varies with both capacitance and voltage. A larger capacitance or higher voltage increases energy storage ability. This concept of energy storage is vital in many technological and medical devices.

Calculating capacitance is crucial in understanding a capacitor's ability to store charge.
Capacitance (C) indicates how much electric charge a capacitor can hold at a given voltage. For a successful calculation, we rearrange the energy formula to solve for \( C \).
The formula becomes: \( C = \frac{2E}{V^2} \), where \( E \) is energy and \( V \) is voltage in volts.

• First, ensure the voltage is in volts before calculation.
• Substitute the known values of energy and converted voltage into the formula.
• Solve the equation to find the capacitance.

For the cardiac defibrillator, after substituting the values, the capacitance is found to be \( 4.27 \times 10^{-5} \, \mathrm{F} \), or \( 42.7 \, \mu \mathrm{F} \). This conversion into microfarads helps convey a meaningful and practical measurement.

A cardiac defibrillator is a medical device used to restore a normal heartbeat. It delivers a dose of electric current to the heart, effectively "shocking" it back into a regular rhythm.
In this application, capacitors play a pivotal role. They store the electrical energy needed for the defibrillator to function efficiently.
The rapid release of stored energy helps achieve the sudden burst necessary to restart the heart.
For this, the defibrillator's capacitor is charged to a high voltage of 7500 volts, sufficient to store 1200 Joules of energy.

• Capacitance and the ability to efficiently deliver energy are key to the effectiveness of the defibrillator.
• A well-designed capacitor ensures the correct amount of energy is released in a controlled manner.
• This precise energy delivery is critical for the device's success in medical emergencies.

Understanding the role of capacitors in such life-saving technology underscores their importance in modern medicine.