Practice Passage Test - 10 | Practice Passages for MCAT PDF Download

Electromagnetism is a branch of physics that deals with the interaction between electric charges and magnetic fields. It is a fundamental force that governs a wide range of phenomena, from the behavior of subatomic particles to the functioning of electrical devices.

One of the key principles in electromagnetism is Coulomb's law, which describes the force between two charged particles. Coulomb's law states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. Mathematically, this can be expressed as F = k(q₁q₂/r²), where F is the force, k is the electrostatic constant, q₁ and q₂ are the charges of the objects, and r is the distance between them.

Moving charges also generate magnetic fields, and the interaction between magnetic fields and moving charges is described by the Lorentz force law. According to this law, a charged particle moving through a magnetic field experiences a force perpendicular to both the direction of motion and the magnetic field. The magnitude of this force can be calculated using the equation F = qvB, where F is the force, q is the charge of the particle, v is its velocity, and B is the magnetic field strength.

The behavior of electric circuits is another important aspect of electromagnetism. Ohm's law, for instance, relates the current flowing through a conductor to the voltage across it and the resistance of the conductor. It states that the current is directly proportional to the voltage and inversely proportional to the resistance. Mathematically, this can be expressed as I = V/R, where I is the current, V is the voltage, and R is the resistance.

Furthermore, electromagnetic induction is a phenomenon where a changing magnetic field induces an electric current in a nearby conductor. This principle is the basis for the functioning of electric generators and transformers, which are essential components in power generation and distribution systems.