Unit 6: Electrostatics and Electric Circuit

These vocabulary flashcards cover the fundamental definitions, laws, and components of Grade 11 Physics Unit 6, focused on Electrostatics and Electric Circuits.

Electrostatics (Static Electricity)

A branch of electricity that deals with the effects resulting from the existence of stationary charges.

Current (Dynamic) Electricity

A branch of electricity that studies the effects produced by moving charges.

Charge ($Q$)

The fundamental property of matter associated with electrons and protons; it is the intrinsic property of subatomic particles.

Elementary Charge ($e$)

The smallest unit of charge carried by one electron or proton, with a magnitude of $|q_e| = 1.6 \times 10^{-19}\,C$.

Quantization of Charge

The property that electric charge always occurs in discrete packets as an integral multiple of the charge of an electron ($q = \pm ne$).

Test Charge ($q_o$)

A very small positive charge used as a detector of an electric field that does not exert a significant force on nearby charges.

Coulomb’s Law

States that any two point charges exert an electrical force on each other that is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

Permittivity of Vacuum ($\epsilon_o$)

A measure of how easy it is for an electric field to be set up in a vacuum, valued at $8.85 \times 10^{-12}\,F/m$.

Electric Field (E-field)

A region in space where a charge experiences an electric force from another charge.

Electric Field Lines

Imaginary lines introduced by Michael Faraday to represent the direction and strength of an electric field; the density of these lines is proportional to the field strength.

Electric Field Strength ($E$)

The force acting per unit positive charge for a stationary point charge, expressed as $E = \frac{F_e}{q_o}$.

Electric Flux ($\Phi$)

A scalar measure of the number of electric field lines crossing a given area, calculated as $\Phi = EA\cos(\theta)$, with units of $N \cdot m^2/C$.

Electric Potential ($V$)

The work done per unit positive charge to move a positive test charge from infinity to its current position within an electric field.

Volt

The SI unit of electric potential, named in honor of Alessandro Volta, defined as 1 Joule per Coulomb ($1\,J/C$).

Electric Potential Energy ($U$)

The energy of a test charge in the vicinity of a source charge, defined by the work done to move the charge within an electric field.

Equipotential Lines/Surfaces

Lines or surfaces connecting points of the same electric potential, where the potential difference and work done to move a charge are zero.

Electric Current ($I$)

The rate of flow of charges through a cross-sectional area, calculated as $I = \frac{\Delta Q}{\Delta t}$ and measured in Amperes ($A$).

Current Density ($J$)

A vector quantity defined as the magnitude of the electric current per cross-sectional area of a conductor ($J = \frac{I}{A}$).

Drift Velocity ($V_d$)

The average velocity with which free electrons get drifted towards the positive terminal under the effect of an applied electric field.

Resistance ($R$)

The electrical property that impedes or opposes the flow of electric current in a conductor, measured in Ohms ($\Omega$).

Ohm’s Law

States that the current flowing through a conductor is directly proportional to the potential difference (Voltage) applied to it ($V = IR$).

Series Connection

A circuit arrangement where components are connected end-to-end to form a single path for electrons to flow, maintaining constant current.

Parallel Connection

A circuit arrangement with more than one path for electrons, where all components are connected across the same potential difference.

Ammeter

A device with very low resistance used to measure current flowing in a circuit, always connected in series.

Voltmeter

A device with very high resistance used to measure the potential difference between two points, always connected in parallel.

Galvanometer

A very sensitive instrument used for measuring small electric currents by deflecting a pointer in a magnetic field.

Potentiometer

A device used to accurately measure electromotive force (EMF) and internal resistance.

Wheatstone Bridge

An arrangement of four resistances used to precisely measure an unknown resistance when the potential difference across the galvanometer is zero.

Kirchhoff’s First Rule (Junction Rule)

States that the total current entering a junction must equal the total current leaving it, based on the law of conservation of charge.

Kirchhoff’s Second Rule (Loop Rule)

States that the sum of the EMFs around any complete loop is equal to the sum of the potential drops, based on the law of conservation of energy.

Capacitor

An electrical component made of two conductors separated by a dielectric, used to store electric charge and energy.

Capacitance ($C$)

The ratio of the amount of charge stored to the potential difference between conductors ($C = \frac{Q}{\Delta V}$), measured in Farads ($F$).

Dielectric

An insulating or non-conducting material (like glass or paraffin) inserted between capacitor plates to increase capacitance.

Dielectric Strength

The maximum electric field strength that a dielectric material can withstand without breaking down and becoming conductive.