Lecture Five: Current of Electricity

What are the three main components of an atom?

Protons, neutrons, and electrons.

What is the charge of a proton?

A proton has a positive charge of +1.6 × 10^-19 C.

What is the charge of an electron?

An electron has a negative charge of -1.6 × 10^-19 C.

What is an electric charge represented by?

The symbol Q.

What is electric current measured in?

Amperes (A).

What is the relationship between charge, current, and time?

I = Q / t, where I is current, Q is charge, and t is time.

What is potential difference also known as?

Voltage.

What symbol represents voltage?

V.

What is the formula relating energy, charge, and voltage?

E = QV.

What does Ohm's Law state?

I = V/R, where I is current, V is voltage, and R is resistance.

What is the unit of resistance?

Ohm.

What is a semiconductor?

A material with electrical conducting properties that are intermediate between conductors and insulators.

How does current flow in a series circuit?

The current is the same at all points in the circuit.

How does current flow in a parallel circuit?

The current is shared between the components.

What happens to a bulb in a series circuit when one bulb goes out?

The circuit is broken and all bulbs go out.

What happens to a bulb in a parallel circuit when one bulb goes out?

The other bulbs stay on.

What does a battery do in a circuit?

A battery uses chemical energy to move charges.

What factors can increase the conductivity of semiconductors?

Raising the temperature and adding small amounts of impurities.

What is the main difference between alternating current (AC) and direct current (DC)?

AC flows in both directions while DC flows in one direction only.