Electric Charges and Forces - Flashcards

Vocabulary flashcards covering key concepts from the lecture notes on electric charges, conductors/insulators, charging methods, and basic atomic structure.

Electric charge

A property of matter due to protons and electrons that leads to electric forces; measured in Coulombs.

qE, qA, Qd, Qb, Qc

Measurement of electric charges

A rod attracts a positively charged hanging ball. The rod is

The amount of positive electric charge approx. = 4.61 × 10^4 C

Find the amount of positive electric charge in 1 gm of sodium (23Na)

atoms. (Note: The nucleus of a sodium atom contains 11 protons, and each mole contains 6.023 × 10²3 atoms)

Proton

Positively charged subatomic particle located in the atomic nucleus.

Electron

Negatively charged subatomic particle that orbits the nucleus.

Coulomb (C)

SI unit of electric charge; 1 C ≈ 6.24×10^18 elementary charges.

Elementary charge (e)

Fundamental unit of electric charge; magnitude of proton’s charge, e ≈ 1.6×10^-19 C.

q (or Q)

Net electric charge of an object; q = (Np − Ne) × e.

Charge quantization

Net charge of macroscopic objects is an integer multiple of the elementary charge e.

Neutral

Having no net electric charge (q = 0).

Positive charge

Charge carried by protons; attracts negative charges.

Negative charge

Charge carried by electrons; the sign is negative.

Conductor

Material through which electric charge moves easily (e.g., metals).

Insulator

Material in which electric charge is largely immobile (e.g., plastic, rubber).

Frictional charging (triboelectric effect)

Charging by rubbing; transfer of electrons between materials due to friction.

Charging by touching (conductive charging)

Charging a conductor by direct contact, allowing charge to flow onto/off the object.

Grounding

Connecting to Earth to redistribute or remove excess charge.

Ionization

Process of removing or adding electrons to atoms, creating ions.

Atom

Basic unit of matter consisting of a nucleus and surrounding electrons.

Nucleus

Central positively charged core of an atom containing protons (and neutrons).

Fundamental unit of charge

Symbolized by e; the smallest unit of electric charge (~1.6×10^-19 C).

Conservation of charge

Charge is neither created nor destroyed; total charge in a closed system remains constant.

Like charges repel

Two positive or two negative charges push away from each other.

Opposite charges attract

A positive and a negative charge attract each other.

Charge distribution on an isolated conductor

Excess charge resides on the surface; the interior field of a conductor at rest is zero.