Physics: Electricity & Magnetism

What are the two types of electric charge and how do like and opposite charges interact?

The two types are positive and negative. Like charges repel each other, while opposite charges attract.

State Coulomb's Law, including its mathematical form and what each variable represents.

Coulomb's Law describes the electrostatic force between two point charges. F = k * |q1 * q2| / r^2, where F is the force, k is Coulomb's constant, q1 and q2 are the magnitudes of the charges, and r is the distance between them.

Define electric field and describe how its direction is determined.

An electric field is a region around a charged particle where a force would be exerted on other charged particles. Its direction is defined as the direction of the force that a positive test charge would experience.

What is electric potential (voltage) and what are its standard units?

Electric potential is the amount of electric potential energy per unit charge at a given point in an electric field. Its standard unit is the Volt (V), which is Joules per Coulomb (J/C).

Define capacitance and explain its primary function in an electrical circuit.

Capacitance is a measure of a component's ability to store electric charge. Its primary function is to store electrical energy in an electric field.

What is electric current and what are its standard units?

Electric current is the rate of flow of electric charge through a conductor. Its standard unit is the Ampere (A), which is Coulombs per second (C/s).

Define electrical resistance and list the factors that affect it in a wire.

Electrical resistance is a measure of the opposition to the flow of electric current. It depends on the material's resistivity, length, and cross-sectional area, and temperature.

State Ohm's Law, including its mathematical form.

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. V = I * R, where V is voltage, I is current, and R is resistance.

How is electric power defined and what is its relationship to voltage and current?

Electric power is the rate at which electrical energy is converted into another form of energy. It is calculated as P = V * I, where P is power, V is voltage, and I is current.

What is a magnetic field and how is its direction typically represented around a bar magnet?

A magnetic field is a region around a magnet or a moving electric charge where magnetic forces are exerted. Its direction is represented by field lines emerging from the North pole and entering the South pole.

Describe the conditions under which a charged particle experiences a magnetic force, and state its direction relative to velocity and magnetic field.

A charged particle experiences a magnetic force only if it is moving relative to the magnetic field. The force is perpendicular to both the velocity of the charge and the magnetic field direction.

What is the fundamental source of all magnetic fields?

All magnetic fields are fundamentally produced by moving electric charges, such as electric currents or the intrinsic spin of elementary particles.

State Faraday's Law of Induction.

Faraday's Law states that a changing magnetic flux through a coil induces an electromotive force (EMF), which is proportional to the rate of change of the magnetic flux.

What is the purpose of Lenz's Law in the context of induced current?

Lenz's Law states that the direction of an induced current will always oppose the change in magnetic flux that caused it, ensuring conservation of energy.

What constitutes an electromagnetic wave, and what is its speed in a vacuum?

An electromagnetic wave consists of oscillating electric and magnetic fields perpendicular to each other and to the direction of propagation. In a vacuum, it travels at the speed of light, 'c'.