Electric and magnetic fields are two fundamental components of electromagnetic phenomena. They are closely related but have distinct characteristics. Here are the main differences between electric and magnetic fields:
Source of influence:
Electric fields are generated by electric charges. Any stationary or moving electric charge creates an electric field around it. The strength and direction of the electric field depend on the magnitude and distribution of the charges.
Magnetic fields are produced by moving electric charges. Whenever there is a current (flow of charges) in a conductor or a moving electric charge, it generates a magnetic field around it.
Nature of influence on charges:
Electric fields exert forces on electric charges. If a charged particle is placed in an electric field, it experiences a force in the direction of the field if it has the same sign as the charge, and in the opposite direction if it has the opposite sign.
Magnetic fields, on the other hand, exert forces on moving charges only. A stationary charge experiences no force in a magnetic field, but a moving charge feels a force perpendicular to both its velocity and the magnetic field direction.
Direction of field lines:
In an electric field, the field lines extend outward from positive charges and terminate at negative charges. The field lines never cross and are always directed away from positive charges and toward negative charges.
In a magnetic field, the field lines form closed loops around the current-carrying conductor. Inside the conductor, the field lines circulate in concentric circles, and outside the conductor, they extend as loops in various directions.
Effect on other fields:
Electric fields can induce magnetic fields and vice versa. When there is a change in an electric field, it can create a magnetic field in the surrounding space, and when there is a change in a magnetic field, it can generate an electric field.
Units of measurement:
The electric field is measured in volts per meter (V/m) or newtons per coulomb (N/C).
The magnetic field is measured in tesla (T) or gauss (G).
Electric fields are vital in the operation of electronic devices, power transmission, and many everyday applications like charging devices, static electricity, etc.
Magnetic fields are crucial for generating electricity in power plants, operating electric motors, magnetic resonance imaging (MRI) in medical applications, and various industrial processes.
Despite their differences, electric and magnetic fields are intrinsically interconnected and together form the electromagnetic field, which is fundamental to many aspects of modern physics and technology. The unification of electric and magnetic phenomena into the electromagnetic theory was one of the significant accomplishments of James Clerk Maxwell in the 19th century.