Magnetic Field Energy Storage Capacity

The energy storing capacity of magnetic field is given by the formula:

U = (1/2) L I^2

where U is the energy stored in the magnetic field, L is the inductance of the coil, and I is the current flowing through it.

Similarly, the energy storing capacity of electric field is given by the formula:

U = (1/2) C V^2

where U is the energy stored in the electric field, C is the capacitance of the capacitor, and V is the voltage across it.

Comparison of Magnetic Field and Electric Field Energy Storage Capacity

The energy storing capacity of magnetic field is about 25,000 times greater than that of electric field. This can be explained by the following reasons:

1. Inductance vs Capacitance

Inductance is a property of a coil that opposes any change in current flowing through it by inducing a voltage in the opposite direction. It is proportional to the square of the number of turns in the coil and the area enclosed by them. As a result, inductance can be increased by increasing the number of turns or the area of the coil.

Capacitance, on the other hand, is a property of a capacitor that opposes any change in voltage across it by storing charge on its plates. It is proportional to the area of the plates and inversely proportional to the distance between them. As a result, capacitance can be increased by increasing the area of the plates or decreasing the distance between them.

Since inductance can be increased more easily than capacitance, the energy storing capacity of magnetic field is higher than that of electric field.

2. Current vs Voltage

The energy stored in a magnetic field depends on the square of the current flowing through the coil, while the energy stored in an electric field depends on the square of the voltage across the capacitor. Since the current flowing through a coil can be much higher than the voltage across a capacitor, the energy storing capacity of magnetic field is higher than that of electric field.

Applications of Magnetic Field Energy Storage

The high energy storing capacity of magnetic field makes it useful in various applications, such as:

1. Inductors in electronic circuits to store energy and filter out unwanted frequencies.

2. Transformers to transfer energy from one circuit to another.

3. Electric motors and generators to convert electrical energy into mechanical energy and vice versa.

4. Magnetic storage devices such as hard disk drives to store digital data.

Conclusion

In summary, the energy storing capacity of magnetic field is about 25,000 times greater than that of electric field due to the higher inductance of coils and the higher current flowing through them. This makes magnetic field useful in various applications where high energy storage is required.