Capacitance Calculator
Calculate voltage, charge, capacitance, and stored energy in capacitors with interactive visualization
Parameters
Controls
Calculated Values
Examples
Example 1: Basic Capacitor
A 100μF capacitor charged to 12V.
- Charge:
- Energy:
Example 2: High Energy Storage
A 1F supercapacitor at 2.7V for energy storage.
- Charge:
- Energy:
Example 3: Small Capacitor
A 10nF capacitor in an electronic circuit.
- Charge:
- Energy:
Visualization
Capacitance and Capacitors
Capacitance is the ability of a system to store an electric charge. A capacitor is a device that stores electrical energy in an electric field by accumulating electric charges on two closely spaced surfaces that are insulated from each other.
The capacitance of a capacitor is defined as the ratio of the electric charge on each conductor to the potential difference between them: C = Q/V. The unit of capacitance is the farad (F), named after Michael Faraday.
The basic relationship between charge (Q), voltage (V), and capacitance (C) is Q = C × V. This equation shows that the charge stored on a capacitor is directly proportional to both the applied voltage and the capacitance value.
The energy stored in a capacitor can be calculated using E = ½ × C × V². This energy is stored in the electric field between the capacitor plates and can be released when the capacitor discharges.
Capacitors are fundamental components in electronic circuits, used for energy storage, filtering, timing, coupling, and many other applications. Their ability to store and release energy quickly makes them essential in power supplies, signal processing, and energy harvesting systems.
Key Concepts
- Charge (Q): Electric charge stored on capacitor plates, measured in coulombs (C)
- Voltage (V): Potential difference across capacitor, measured in volts (V)
- Capacitance (C): Ability to store charge, measured in farads (F)
- Energy (E): Stored electrical energy, measured in joules (J)
- Basic Formula: Q = C × V
- Energy Formula: E = ½ × C × V²
Real-World Applications
- Energy Storage: Storing electrical energy for later use
- Filtering: Removing unwanted frequency components from signals
- Timing: Creating time delays in electronic circuits
- Coupling: Passing AC signals while blocking DC
- Power Factor Correction: Improving efficiency in power systems
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Physics Equations
Step-by-Step Solution
See how the main results are calculated.
Step 1: Identify Known Values
List the given values from the problem:
Equation:
Calculation:
Explanation:
We start by identifying what values we know and what we need to find.
Step 2: Apply Capacitance Formula
Use the capacitance formula to find the charge:
Equation:
Calculation:
Explanation:
The basic capacitance formula relates charge, capacitance, and voltage. To find charge, we multiply capacitance by voltage.
Step 3: Calculate Stored Energy
Use the energy formula to find stored energy:
Equation:
Calculation:
Explanation:
The energy stored in a capacitor is proportional to the square of the voltage and the capacitance value.
Frequently Asked Questions (FAQ)
What is capacitance?
Capacitance is the ability of a system to store an electric charge. It is defined as the ratio of charge to voltage: C = Q/V.
What is the unit of capacitance?
The unit of capacitance is the farad (F), named after Michael Faraday. One farad is equal to one coulomb per volt.
How do I calculate stored energy in a capacitor?
The energy stored in a capacitor is given by E = ½ × C × V², where C is capacitance and V is voltage.
What happens if I increase the voltage?
If capacitance remains constant, increasing voltage will proportionally increase charge according to Q = C × V. Energy will increase as the square of the voltage.
Why is capacitance important?
Capacitance determines how much charge a capacitor can store at a given voltage. It affects energy storage capacity, filtering characteristics, and timing in electronic circuits.
What happens when voltage is zero?
When voltage is zero, no charge is stored on the capacitor (Q = 0) and no energy is stored (E = 0). The capacitor is completely discharged.
How do I use this calculator?
Enter any two values (voltage, charge, or capacitance) and the calculator will automatically calculate the third value. You can also enter all three values to verify they satisfy Q = C × V.
Practice MCQs
- If capacitance is 10μF and voltage is 5V, what is the charge?
- What is the energy stored in a 100μF capacitor at 12V?
- If charge is 2C and voltage is 4V, what is the capacitance?
- What happens to charge if voltage doubles and capacitance stays the same?
- Which formula is NOT valid for capacitors?
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