RT4IMEQMA Preliminary Reviewer PDF

RT4IMEQMA MARY FAITH BAUTISTA, RRT 2. Insulator – materials that do not allow the flow of Electrification – occurs due to the movement of negative electrons. electric charges....

RT4IMEQMA MARY FAITH BAUTISTA, RRT 2. Insulator – materials that do not allow the flow of Electrification – occurs due to the movement of negative electrons. electric charges. ex: glass, plastic, wood, rubber, and paper. electric charges being added and subtracted in an object. 3. Semi-Conductor – materials that sometimes behave as METHODS OF ELECTRIFICATION conductor and in other conditions behave as insulator. ex: Silicon (Si) and Germanium (Ge) Contact – occurs when two objects come in contact. 4. Superconductor -materials that allow the flow of Friction – occurs when two objects are rubbed together. electrons (like conductor) but possess no resistance to Induction – is a method used to charge an object without electrons to flow. touching each other. ex: Niobium (Nb) and Titanium (Ti) ELECTRIC CHARGES Ohm’s Law – states that the current passing through a Proton – positively charged (+) Notes: conductor is directly proportional to the potential Electron – negatively charged (-) 1 e- = 1.6 x 10 -19 C difference and inversely proportional to the resistance. Neutron – neutrally charged (0) 1 C = 6.3 x 10 18 e – Formula : V = IR TWO STUDIES OF ELECTRICITY where : Electrostatics – study of stationary electric charges. V = electric potential (Volts/v) Electrodynamics -study of electric charges in motion. I = electric current (Ampere/A) R = electric resistance (ohms/Ω) FOUR ELECTROSTATIC LAW 1. Unlike charges attracts ; like charges repel. Electric Current - flow of the electric charge 2. Coulomb’s Law - states that the electrostatic force is through a medium. This charge is typically carried directly proportional to the product of the electrostatic by moving electrons in a conductor such as wire. charges and inversely proportional to the square of the distance between them. 2 TYPES OF ELECTRIC CURRENT 3. Electric Charge Distribution - states that the electric charge Direct Current (DC) - electrons flowing in one distribution is uniform throughout or on the surface. direction. 4. Electric Charge Concentration - states that electric charges -produced from sources such as batteries, fuel are concentrated along the sharpest curvature of the cells, and solar cells. surface. Alternating Current (AC) – current in which Electrostatic Force – the force of attraction between unlike electrons oscillate back and forth. AKA 60Hz charges or repulsion between like charges, which is due to -Come from a source such as a power plant. the electric field; Holds the electron in an orbit. Take note that the x-ray tube only operates in direct current (DC) that’s why we need rectifiers Coulomb’s Law Formula: to convert AC (electric company) to DC. Electric Power – the rate at which electric energy where: is transferred by an electric circuit. F = electrostatic force (Newton/N) K = constant ( 9.0 x 109 Nm2/C2) Formula : P = IV or P = I2R Q1 and Q2 = electric charges (Coulomb/C) r/d = distance (meter/m) where : FOUR ELECTRIC STATES OF MATTER P = power (Watts/W) 1. Conductor – materials that allow the flow of electrons. V = Voltage (Volts/V) ex: copper, gold, metals, and water. I = Current (Ampere/A) R = Resistance (ohms/Ω) This reviewer is for RT4IMEQMA students only. RT4IMEQMA MARY FAITH BAUTISTA, RRT Electromagnetism – the study of electromagnetic Magnetism – force where the objects are attracted and force. It is a type of interaction that occurs between repelled to one another. electrically charged particles. Magnetite – a magnetic oxide of iron. Michael Faraday – discovered induction in 1831. rod-like stone; the most magnetic of all naturally -made the first dynamo in 1837. occurring minerals on Earth. Heinrich Lenz – discovered the second law of electromagnetism. Magnetic Domain – an accumulation of many atomic magnets with their dipoles aligned. Notes: Magnetic Moment – nuclear magnetic dipole. Luigi Galvani – accidentally discovered battery. Magnetic Permeability – ability of a material to attract Alessandro Volta – invented voltaic pile; made up of the lines of a magnetic field density. sandwich copper and zinc. Hans Oersted – states that the electric current creates Magnetic Susceptibility – the degree to which the a magnetic field strength. material can be magnetized. 4 LAW OF ELECTROMAGNETISM CLASSIFICATION OF MAGNETS Natural Magnet – magnets that occur in nature. 1. Faraday’s Law – magnetic fields cannot be used to Ex: earth and magnetite generate electric current. Permanent Magnet – strong magnetic fields that do not 2. Lenz’ Law – states that the direction of induced current fade. Also known as artificial magnet. opposes the action that induces it. Ex: compass, horseshoe magnets and 3. Electric Generator – device that converts mechanical refrigerator magnets energy into electrical energy. Also called energy converter. Electromagnets – temporary magnets produced by 4. Electric Motor – device that converts mechanical means of electric current; coil of wire wrapped around energy to electrical energy. an iron core. Ex: MRI machine Notes: Right – hand – rule FOUR MAGNETIC STATES OF MATTER Thumb – motion of the current Non/Diamagnetic - unaffected or does not retain the Curled fingers – direction of magnetic field magnetic properties. Ex: paper, glass, plastic, rubber, and wood Transformer – an electrical device that either Paramagnetic - lies between ferromagnets and increases or decreases the voltage in a circuit. diamagnets. Ex: Gadolinium (MRI contrast agent) Winding – usually made with single primary Ferromagnetic - can be strongly magnetized. winding and secondary can have less than one Ex: Aluminum, Nickel, Cobalt, and Iron winding. Core – design to form a closed circuit. Made up of MAGNETIC LAWS thin sheets of soft iron. 1. Dipoles – states that dividing a magnet into smaller pieces will only create smaller magnets with north and 3 TYPES OF TRANSFORMERS south poles. Closed core – primary coil is on one leg and the Attraction and Repulsion - like magnetic pole repel ; secondary coil is on the other leg. unlike magnetic pole attracts. Shell type – primary and secondary coils wound Magnetic Induction – states that some materials can be up around the central limb. magnetic through induction. - More efficient than the closed core and most Notes: currently used type of transformer. Autotransformer – has one winding and varies Earth’s magnetic field is approximately 50 voltage and current by self-induction. microT at the equator. Both poles have 100 microT. This reviewer is for RT4IMEQMA students only.