Physics: Circuits, Electronics, and Nuclear Energy Lecture Notes

Comprehensive vocabulary flashcards covering circuit types, electrical units, historical atomic models, electronics components, and nuclear physics concepts including radioactivity and detection methods.

Circuit

Path between two or more points along which an electrical current can be carried.

Series Circuit

Closed Circuit in which the current has only one path to take where current stays same and voltage changes with resistance.

Parallel Circuit

Closed Circuit in which the current divides into two or more paths before recombining to finish the circuit; voltage stays same and current changes with resistance.

Kirchoff's law

Total current entering a junction must equal the total current exiting a junction.

Primary Cell

A dry cell used only once, typically containing a dry paste such as ammonium chloride, characterized by being small, portable, and having high internal resistance.

Secondary Cell

A wet cell that can be reused, typically containing a wet liquid such as lead acid, characterized by being large, having low internal resistance, and producing large current.

Ohm's Law

Current flowing through a resistor at a constant temperature is directly proportional to the voltage across the resistor, expressed as $R = V / I$.

Electric Charge

Physical property of matter that causes it to experience force when placed in an electromagnetic field, measured in Coulombs ($Q$).

Electric Current

Flow of electric charge, measured in Amperes ($I$).

Electric Potential

Electric potential energy per unit charge, measured in joules per coulomb ($volts$).

Electric Power

Rate at which electrical energy is transferred by an electric circuit, calculated as $P = IV$ and measured in Watts ($P$).

Kilowatt-hour

The total energy in kilowatt-hours is the power in kilowatts multiplied by the time in hours; used as a billing unit for energy delivered by electric companies.

Electric Field

A region in which an electric charge experiences a force of electrical origin.

Ampere

The SI unit of current, equivalent to 1 ampere when the rate of flow of charge is 1 coulomb per second through a point.

Alternating current

Current that reverses direction with time.

Direct current

Current that does not change current with time.

Static Electricity

An imbalance of electric charges within or on the surface of a material.

Friction (Static Electricity)

Process where electrons transfer from one object to another that are rubbed together.

Conduction (Static Electricity)

Process where electrons move from one object to another by direct contact.

Induction (Static Electricity)

Process where a charged object is brought near but does not touch a neutrally charged object, causing it to become charged.

Electrical Conductors

Material where charges move easily, such as metals which contain free electrons.

Electrical Insulators

Material where charges cannot move easily because electrons do not move freely.

Van Graff Machine

Device used to provide very high voltages to accelerate charged particles to high velocities.

Xerography

The process used in photocopiers where electrostatics is used to attract ink to paper.

Dust Precipitators

Electrostatic devices that remove smoke and dust from waste gases going up factory chimneys.

Period

Time it takes for alternating current to change its direction.

Root mean square (RMS)

A value calculated as $\text{RMS} = ext{Peak Value} / ext{\sqrt{2}}$.

Semiconductor Diode

Crystalline piece of semiconductor material with a P-N junction connected to two electrical terminals.

Capacitor

Device used to store charge.

Doping

The process of adding impurities to a substance.

N type Semiconductor

A semiconductor doped with elements of group five (like phosphorus or arsenic) resulting in extra electrons.

P type Semiconductor

A semiconductor doped with elements of group three (like boron or aluminum) resulting in 'holes'.

Rectification

The process of converting AC to DC.

Democritus

The historical figure who named the smallest piece of matter 'atomos'.

JJ Thompson

Scientist who discovered the electron and proposed the Plum pudding model.

Ernest Rutherford

Scientist who proposed the Planetary Model of the atom.

Geiger Marsden

Experimenters who shot positively charged alpha particles at gold foil, discovering the positively charged nucleus and that the atom is mostly space.

Neils Bohr

Scientist who proved mathematically that electrons could exist in shells at certain distances from the nucleus.

James Chadwick

Scientist who discovered the Neutron, revolutionizing atomic structure understanding.

Radioactivity

Spontaneous disintegration ('decay') of unstable atomic nuclei.

Alpha (\alpha)

A radioactive particle made up of two protons and two neutrons.

Beta (\beta)

A high speed electron emitted during radioactive decay.

Gamma (\gamma)

Photons emitted spontaneously by a radioactive substance.

Half Life

The time taken for the mass or activity of a given sample of a radioisotope to decay to half of its value.

Parent Nuclide

The decaying nuclide during radioactive decay.

Daughter Nuclide

The new nuclide produced by radioactive decay.

Nuclear Fission

The splitting of atoms.

Energy Fission

The joining together of atoms.

Cloud Chamber

Detection device filled with super saturated water vapor that makes paths of moving particles visible as white lines of condensed droplets.

Geiger Muller tube

Device that detects ions produced when alpha, beta, or gamma radiation interact with gas at low pressure.

Ratemeter

An instrument connected to a GM tube that gives the rate of emission.

Scalar

An instrument connected to a GM tube that counts the emissions.