Electricity and Magnetism Basics

Alternators and Electrical Circuits

• An alternator generates an Alternating Current (AC).
• The main function of an alternator is to convert mechanical energy into electrical energy.
• An alternator produces electricity by using electromagnetic induction to convert the mechanical energy of the rotating armature into electrical energy.

Electrical Current and Resistance

• One ampere is the rate of flow of one coulomb per second.
• If the current flowing in a circuit is 3 amperes, 15 coulombs of charge pass through the circuit in 5 seconds.
• If the resistance in a circuit increases, the rate of current flow decreases.

Magnetism

• Ampere-turns (NI) are a measurement of magnetism.
• Ampere-turns are the product of the number of turns of wire (N) and the current flow (I).
• Ampere-turns contribute to the functioning of an alternator by increasing the magnetic field strength.

Arcs

• An arc is a bright, hot, and highly conductive plasma that forms when an electric current flows through a gas, such as air.
• An arc can occur when there is a spark or a flash of electricity between two conductive points.

Armature and Commutator

• The armature is the rotating part of a motor or generator that rotates in a magnetic field to produce electricity.
• The typical components found in the armature of a motor or generator are the commutator, brushes, and windings.
• The commutator is a mechanical device that switches the current flow to the armature windings as it rotates.

Atomic Structure

• The smallest part of an element that contains all its properties is an atom.
• Protons are found in the nucleus of an atom.
• The atomic number of an element represents the number of protons in the nucleus of its atoms.

Force and Atoms

• The force that causes one object to pull another object to itself is known as attraction or gravitational force.
• In the context of forces, attraction is the action of one object pulling another object to itself.

Rectification of AC Voltage to DC Voltage

• The term 'average' refers to the average value of an AC waveform when it is rectified to DC voltage.
• The ratio of rectified DC voltage depends on the type of AC waveform.
• The ratio of rectified DC voltage is determined by the peak value of the AC waveform.

Transistors

• The main function of the base in a transistor is to control the flow of current between the collector and emitter.
• The semiconductor region between the collector and emitter of a transistor is called the base.
• The base controls the flow of current between the collector and emitter.

Batteries and Bidirectionality

• The primary function of a battery is to store electrical energy.
• A bidirectional object can either supply or absorb electrical energy, unlike a battery which can only supply energy.
• A branch circuit extends beyond the main circuit and begins at the main circuit breaker or fuse.

Circuit Components and Protective Devices

• The function of a circuit protective device is to interrupt the flow of current in a circuit under abnormal conditions.
• The purpose of a carbon film resistor is to reduce the voltage or current in a circuit.
• Carbon film resistors are produced by depositing a thin film of carbon on a ceramic substrate.

Cardiopulmonary Respiration (CPR)

• The primary purpose of cardiopulmonary respiration (CPR) is to restore blood circulation and breathing in a person who has stopped breathing or whose heart has stopped beating.
• Alternation between closed heart massage and artificial respiration is significant in CPR.

Cells and Energy Conversion

• The primary function of a cell is to convert energy and produce ATP (adenosine triphosphate).
• A cell converts chemical energy into ATP through cellular respiration.
• A cell converts and produces chemical energy.

Circuit Breakers and Coercive Force

• The primary purpose of circuit breakers is to interrupt the flow of current in a circuit under abnormal conditions.

• Circuit breakers are rated according to their current-carrying capacity and voltage rating.

• When circuit breakers open under abnormal current flow, they disconnect the circuit.

• Coercive force is the magnetic field strength required to demagnetize a magnetic material.

• Coercive force has the effect of demagnetizing a magnetic material.

• Coercive force relates to the hysteresis loop of a magnetic material, which describes the relationship between the magnetic field strength and magnetization.