⚡ Electrical
Electrical units used in electronics and engineering.
Electrical Fundamentals ⚡
Electricity powers everything from tiny sensors to household appliances. Understanding voltage, current, and resistance is crucial for designing, troubleshooting, and safely using circuits.
This section introduces the three core electrical concepts and shows how they relate to each other.
Key Facts
- Voltage (V) measures electric potential difference - the 'pressure' pushing electrons through a circuit.
- Current (A) measures the flow of electric charge through a circuit.
- Resistance (Ω) measures how much a component opposes current flow, controlling and protecting circuits.
- Ohm’s Law relates the three: V = I × R
Formulas
V = I × R- Voltage equals current times resistanceI = V ÷ R- Current equals voltage divided by resistanceR = V ÷ I- Resistance equals voltage divided by current
Real-World Electrical Examples
- AA battery: 1.5 V, drives small currents for low-power devices
- USB power: 5 V, 2 A typical charging current
- LEDs: ~10–20 mA current, requires appropriate resistor to prevent burnout
- Smartphone charging: 1–2 A current at 5 V voltage
- Resistors in electronics: 10 Ω – 10 kΩ to control and divide current
FAQs
Why do we use volts, amps, and ohms?
These units describe the essential properties of electricity: potential (V), flow (A), and opposition (Ω), allowing proper design and measurement of circuits.
How do voltage, current, and resistance relate?
Ohm’s Law (V = I × R) defines the relationship. Knowing any two allows calculation of the third.
Why is it important to match units?
Using incorrect scales (millivolts vs volts, milliamps vs amps) can damage components or lead to measurement errors.
Can I measure small currents and voltages safely?
Yes - using mV and mA units allows precise measurement without risking damage to circuits or instruments.