Electrical Circuits Basics

Study Notes

A circuit is a path through which electric current flows
Types of circuits:
- Series circuit: components connected one after the other
- Parallel circuit: components connected between the same two points
Circuit components:
- Conductors: allow electric current to flow (e.g. wires)
- Insulators: prevent electric current from flowing (e.g. rubber)
- Switches: control the flow of electric current
- Resistors: reduce the voltage in a circuit
- Capacitors: store electric energy

Ohm's Law states: V = I × R
- V: voltage (potential difference) in volts (V)
- I: current in amperes (A)
- R: resistance in ohms (Ω)
Ohm's Law is a linear relationship between voltage, current, and resistance
Can be rearranged to solve for any of the three variables

Resistance: opposition to the flow of electric current
Measured in ohms (Ω)
Factors affecting resistance:
- Material: different materials have different resistivities
- Length: longer wires have greater resistance
- Cross-sectional area: thicker wires have less resistance
- Temperature: resistance increases with temperature
Types of resistors:
- Fixed resistors: have a fixed resistance value
- Variable resistors: can be adjusted to change the resistance value

Electric potential: potential energy per unit charge at a point in a circuit
Measured in volts (V)
Also known as voltage or electromotive force (EMF)
Electric potential difference: the difference in electric potential between two points
Electric potential is a scalar quantity

Electricity is the flow of electrons through a conductor
Electric charge: a fundamental property of matter
- Positive charge: protons
- Negative charge: electrons
Electric current: the flow of electrons through a conductor
- Measured in amperes (A)
Electric power: the rate at which electric energy is transferred
- Measured in watts (W)
- Calculated using the formula: P = I × V
Electric energy: the total work done by an electric current
- Measured in joules (J)
- Calculated using the formula: E = P × t

States the relationship between voltage, current, and resistance: V = I × R
Voltage (V) is measured in volts, current (I) in amperes, and resistance (R) in ohms
Linear relationship between V, I, and R

Opposition to the flow of electric current
Measured in ohms (Ω)
Factors affecting resistance: material, length, cross-sectional area, and temperature
Types of resistors: fixed and variable

Potential energy per unit charge at a point in a circuit
Measured in volts (V), also known as voltage or EMF
Electric potential difference: difference in electric potential between two points
Scalar quantity

Electric charge: a fundamental property of matter, with positive (protons) and negative (electrons) charges
Electric current: flow of electrons through a conductor, measured in amperes (A)

Electric power: rate at which electric energy is transferred, measured in watts (W)
Calculated using the formula: P = I × V
Electric energy: total work done by an electric current, measured in joules (J)
Calculated using the formula: E = P × t