Theddy Physics Test

Ohm’s Law

V=IR (Voltage = Current × Resistance).

Series Circuit Brightest Bulb

The bulb with the highest resistance.

Parallel Circuit Brightest Bulb

The bulb with the lowest resistance.

Electrical Power Formula

P=IV, P=I²R, or P=V²/R.

Total Resistance in Series

R_total = R1 + R2 + …

Total Resistance in Parallel

1/R_total = 1/R1 + 1/R2 + …

Compass Needle Direction

Points north due to attraction to Earth's magnetic south pole.

Magnetizing an Iron Nail

Stroke it with a magnet in one direction or wrap it in a current-carrying coil.

Energy Conversion in Motors vs. Generators

Motor: Electrical → Mechanical; Generator: Mechanical → Electrical.

Strengthening an Electromagnet

More coils, higher current, or a stronger core (e.g., iron).

Earth’s Magnetic Field Creation

Created by molten iron moving in the outer core.

Helium-4 Composition

2 protons, 2 neutrons, 2 electrons.

Alpha Decay Definition

Emission of a helium nucleus from an unstable atom.

Most Penetrating Radiation

Gamma rays.

Half-Life Definition

Time for half of a radioactive sample to decay.

Distinguishing Isotopes

Same protons (atomic number), different neutrons (mass number).

Voltage Analogy

Water pressure in a hose (the 'push').

Current Analogy

Water flow rate in a hose (electrons moving).

Motor vs. Generator Mnemonic

M for Motion (motor), G for Grid (generator).

Brightness in Series Circuits

Related to I²R.

Brightness in Parallel Circuits

Related to V²/R.

Geographic vs. Earth’s Magnetic Poles

Geographic North ≈ Magnetic South (where compass points).

Beta Decay Definition

Emission of an electron or positron from an unstable nucleus.

Gamma Radiation Nature

High-energy photons (electromagnetic radiation) emitted from a nucleus.

Nuclear Fission

Splitting of a heavy nucleus into lighter nuclei, releasing energy.

Nuclear Fusion

Combining of light nuclei to form a heavier nucleus, releasing energy.

Factors Affecting Resistance

Material, length, area, and temperature.

Kirchhoff's Current Law

Total current entering a junction equals total current leaving it.

Kirchhoff's Voltage Law

Sum of voltages around a closed loop is zero.

Magnetic Field Lines

Lines showing the direction and strength of a magnetic field; go from north to south.

Electromagnetic Induction

Production of voltage across a conductor moving through a magnetic field.

Lenz's Law

Induced current opposes the change that caused it.

Electrical Resistance

The measure of opposition to electric current in a circuit; measured in ohms (Ω).

Series Circuit

A circuit with only one path for current to flow; components are connected end-to-end.

Parallel Circuit

A circuit with multiple paths for current to flow; components are connected side-by-side.

Electrical Power

The rate at which electrical energy is transferred; measured in watts (W).

Magnetic Field

A region of space around a magnet or current-carrying wire where magnetic forces are exerted.

Electric Motor

A device that converts electrical energy into mechanical energy using magnetic fields.

Electric Generator

A device that converts mechanical energy into electrical energy using magnetic fields.

Electromagnet

A type of magnet made by wrapping a wire coil around a ferromagnetic core and passing an electric current through the wire.

Electromagnetic Induction

The process by which a changing magnetic field induces a voltage in a nearby circuit.

Radioactivity

The spontaneous emission of particles or energy from unstable atomic nuclei.

Nuclear Fission

A nuclear reaction in which a heavy nucleus splits into two or more smaller nuclei, releasing a large amount of energy.

Nuclear Fusion

A nuclear reaction in which two or more light nuclei combine to form a heavier nucleus, releasing a large amount of energy.

Half-Life

The time required for half of the radioactive atoms in a sample to decay.

Isotopes

Atoms with the same number of protons but different numbers of neutrons.