Chapter 16 Electric charge and electric field16-1 Static Electricity; Electric Charge and its conservation

Static electricity: When charges is gathering on an object or its surface, it forms an electrostatic charge. Electrostatic phenomenon is divided into two types, positive and negative electrostatic. Electric charge: the unit of electricity.Unlike charges attract; like charges repel.

Law of conservation of electric charge: no net electric charge can be created or destroyed; the net amount of electric charge produced in any process is zero.

16-2 Electric charge in the atomPolar: even though atoms are neutral, their charge is not distributed uniformly.

16-3 insulator and conductors.Nonconductors(insulators), conductors, semiconductors. (whether charge can easily go through or not)

16-4 induced charge; electroscopeInduce:

Electroscope:

Coulomb’s law: ( ), (

) ( , )Electrostatics: charges at rest.Point charge.Superposition principle: electric forces add as vectors.

16-7 the electric field

Electric field:

16-8 field linesElectric field line:

16-9 Electric fields and conductors

Chapter 17 electric potential energy and potential differenceWork done by electric field: Potential energy:

Electric potential:

Voltage:

Equipotential lines:

Capacitance: Charge storage at given potential difference

( )

Capacitor: a device that can store electric charge, and consists of two conducting objects (usually plates or sheets) placed near each other but not touching.

Chapter 18 Electric currentsElectrode: Location where redox reaction takes place and decompose electrolyte solutionElectric cell, battery.Difference between terminal and electrode:

Structure of battery:

Electric current: any flow of charge.

Current intensity:

Ampere:

Ohm’s law: (only for pure resistance circuit)

Resistivity: ρ, Ω·m, depends on material

Resistance:

Electric power:

Alternating current:

(RMS: Root-Mean-Square)

Chapter 19: DC CircuitsElectromotive force: a device that transforms one type of energy into electric energy. (EMF, not a kind of force)

(terminal voltage, electromotive force, current x internal

resistance)

Resistors in series:

Resistors in parallel:

Capacitors in parallel:

Capacitors in series:

Current related laws: Kirchhoff’s first rule (junction rule): at any junction point, the sum of all

currents entering the junction must equal the sum of all currents leaving the junction.

Kirchhoff’s second rule (loop rule): the sum of the changes in potential around any closed path of a circuit must be zero.

RC circuits:

The function of previous curve:

And thus,

τ: time constant,

Chapter 20 Magnetism20-1 Magnets and magnetic fieldNorth pole, South pole (magnetic field lines originate from north pole)/magnetic declination, angle of dip/Electric current produces magnetic field.

Right hand rule: determine the direction of the magnetic field relative to the current.

Magnetic force: (cross product, or right/left

hand rule)

Magnet generated by line currency:

Solenoids and Electromagnets:

Ampere’s Law:

Magnetic dipole moment:

Ferromagnetic, paramagnetic, Diamagnetic

Chapter 21 Electromagnetic induction and Faraday’s law21-1 induced EMFA changing magnetic field induces an emf. (electromagnetic induction)

Magnetic flux: (unit: weber, )

Faraday’s law of induction:

Lenz’s law: a current produced by an induced emf moves in a direction so that its magnetic field opposes the original change in flux.

(motional emf, Blv are perpendicular with each other.)

A changing magnetic field induces an electric field:

Generator’s induced emf:

Transformer and transmission of power:

(primary coil, secondary coil [amount of loops], voltage, currency)

Mutual inductance: if two coils of wire are near one another, a changing current in one will induce an emf in the other.

Self-inductance: when a changing current passes through a coil or solenoid, a changing magnetic flux is produced inside the coil, and this turn induces an emf. (Answer of Max’s problem)

Chapter 22 electromagnetic wavesMaxwell’s equations:1. A generalized form of Coulomb’s law known as Gauss’s law that relates

electric field to its source, electric charge.2. A similar law for the magnetic field, except that magnetic field lines are

always continuous—they do not begin or end (as electric field lines do, on charges)

3. An electric field is produced by a changing magnetic field (Faraday’s law)4. A magnetic field is produced by an electric current (Ampere’s law), or by a

changing electric field. Maxwell: (a changing electric field will produce a magnetic field)

How electromagnetic waves are produced:

(AC circuit only)

Accelerating electric charges give rise to electromagnetic waves.

Frequency/ light speed/ wavelength:

Wave’s region.