PHYSICS: INTRODUCTION TO BASIC CONCEPTS
ELECTRICITY
Electricity is the flow of electric charge, typically carried by moving electrons in a conductor such as a wire. It is a
fundamental aspect of nature that provides power for devices, lights, and appliances. The study of electricity
covers both static and dynamic forms of electrical charge.
Key Concepts in Electricity
1. Electric Charge (Q):
oThe basic property of matter that causes it to experience a force when placed in an electric field.
oMeasured in Coulombs (C).
oThere are two types of electric charges: positive (protons) and negative (electrons).
2. Electric Current (I):
oThe flow of electric charge through a conductor.
oMeasured in Amperes (A).
oFormula:
oWhere:
I = current (in amperes, A)
Q = electric charge (in coulombs, C)
t = time (in seconds, s)
3. Voltage (V):
oAlso called electric potential difference or electromotive force (EMF), it is the difference in
electric potential between two points in a circuit.
oMeasured in Volts (V).
oFormula: V=IR
o Where:
V= voltage (in volts, V)
I = current (in amperes, A)
R = resistance (in ohms, Ω)
4. Resistance (R):
oThe opposition to the flow of electric current in a material.
oMeasured in Ohms (Ω).
oFormula (from Ohm’s Law): R=V/I
o Where:
R = resistance (in ohms, Ω)
V = voltage (in volts, V)
I = current (in amperes, A)
5. Power (P):
oThe rate at which electrical energy is transferred or consumed in a circuit.
oMeasured in Watts (W).
oFormula: P=IV
oWhere:
P = power (in watts, W)
