Electrification and Electrostatics

• Electrification is the addition and removal of electrons.

Methods of Electrification

• Friction occurs when two objects are rubbed together
• Contact occurs when two objects come in contact
• Induction is a method used to charge an object without touching the object

Two Studies of Electricity

• Electrostatics is the study of stationary electric charges
• Electrodynamics is the study of electric charge in motion

Four General Laws of Electrostatics

• Unlike charges attract; like charges repel

• Coulomb's Law

• Electric charge distribution indicates that the electric charge distribution is uniform throughout the surface

• Electric charge concentration indicates that electric charges are concentrated along the sharpest curvature of the surface

• Electrostatic force is the attraction between unlike charges and the repulsion between like charges due to the electric field

• Alessandro Volta discovered the battery and named the cell the battery as "voltaic pile" made of sandwiched copper and zinc

• Hans Oersted established the link between electricity and magnetism

• Luigi Galvani observed the twitching of the legs of the frog during dissection when touching two metals

States of Matter

• Conductors are materials that allow the flow of electrons, for example, copper and aluminum
• Insulators are materials that do not allow the flow of electrons, for example, plastic, wood, glass, rubber, and paper
• Semi-conductors are materials that sometimes behave as insulators or conductors, for example, silicon (Si) and germanium (Ge)
• Superconductors are materials that allow the flow of electrons, like a conductor, but possess no resistance to electron flow, for example, niobium and titanium

Two Types of Electric Current

• Direct Current (DC) has electrons flowing in one direction along the conductor

• Alternating Current (AC) has electrons oscillating back and forth

• Rectifier is a mechanical device that converts alternating current to direct current

• Rectification is the process of converting alternating current to direct current

• X-ray tubes only operate in DC(200V)

• Rectifiers are needed to convert AC to DC

• Ohm's Law indicates that the current passing through the conductor is directly proportional to the potential difference and inversely proportional to the resistance

• Ohm's Law Formula: V = IR, where V (Volts) is electric potential, I (Ampere) is electric current, and R (Resistance) is electric resistance (Ω)

• Electric current is the ratio of the electric potential across the circuit element to the resistance, with SI unit Ampere (A), and I = V/R

• Electric potential is the product of resistance and current, with SI unit Volts, and V = IR

• Electric resistance is the ratio of the electric potential across the circuit element to the current, with SI unit Ohms Ω, and R = V/I

• Coulomb's Law Formula: F = K * Q1Q2 / r^2, where F is electrostatic force (Newton), K is a proportional constant (8.99 X 10^9 Nm²/C²), Q1 and Q2 are electric charges (Coulomb), and R is distance (meter)

Electric Circuits

• Series circuits have all circuit elements connected in a line along the same conductor
• Rules for series circuit: RTOTAL = R1 + R2 + R3..., ITOTAL = I1 = I2 = I3..., VTOTAL = V1 + V2 + V3...
• Parallel circuits contain elements that are connected at their ends rather than lying in a line along a conductor
• Rules for parallel circuit: 1/RTOTAL = 1/R1 + 1/R2 + 1/R3..., ITOTAL = I1 + I2 + I3..., VTOTAL = V1 = V2 = V3...