Electrical Calculator

Simple circuit calculation

Voltage is like a force that pushes electricity through wires.
Think of it like water pressure in a hose. The higher the voltage, the stronger the push.
Examples:
• AA battery: 1.5V
• Phone charger: 5V
• Car battery: 12V
• House outlet: 120V (US) / 240V (UK)
V
Current is how much electricity flows through the wire.
It's like how much water flows through a hose. More current means more electricity.
Examples:
• LED light: 0.02A
• Phone charging: 1-2A
• Laptop: 3-5A
• Microwave: 10-15A
• Hair dryer: 12-15A
A
Resistance is how much something fights against electricity flowing through it.
It's like rocks in a river. More resistance means electricity moves slower.
Examples:
• Copper wire: 0.001Ω
• LED resistor: 220Ω
• Light bulb: 100-500Ω
• Heating element: 10-50Ω
• Human body: 1000Ω
Ω
Power is how much energy something uses.
It's like how hard you have to pedal a bike. More power means using more energy.
Examples:
• LED light: 5-10W
• Phone charger: 10-20W
• Laptop: 50-90W
• Microwave: 1000W
• Hair dryer: 1500W
W
Cost per kWh is how much you pay for electricity.
It's like the price per gallon of gas. This helps calculate how much it costs to run something.
Examples:
• US average: $0.12/kWh
• California: $0.25/kWh
• Texas: $0.11/kWh
• New York: $0.20/kWh
$
V = I x R     P = V x I

Advanced Aspects of Ohm's Law

Non-linear and Complex Materials:

In real-world materials, resistance might not remain constant across all conditions. Semiconductors, superconductors, and other non-linear materials might not follow Ohm's Law in the simple sense. For instance, in devices like diodes and transistors, the relationship between voltage and current is more complicated.

Temperature Dependence:

The resistance of most materials changes with temperature. This means Ohm's Law in real applications can become more nuanced because the resistance R isn't constant. Special materials like thermistors and resistance temperature detectors (RTDs) are designed to exploit this relationship.

Frequency Dependence (AC Circuits):

In alternating current (AC) circuits, resistance is often extended to impedance, which accounts not only for resistance but also for reactance due to capacitors and inductors. Impedance Z replaces R in Ohm's Law for AC circuits:

V = I x Z

In this case, the relationship between voltage, current, and impedance can become more complex due to phase shifts, resonance, and frequency-dependent effects.

Quantum and Relativistic Effects:

At the quantum level, materials like graphene exhibit very unique properties that can challenge traditional interpretations of Ohm's Law. Quantum mechanics and relativistic effects might modify how we understand the behavior of electrons in these materials.

Superconductivity:

In superconducting materials, resistance drops to zero below a certain critical temperature. Ohm's Law doesn't apply in the traditional sense because the current flows without resistance, and the concept of "voltage drop" across the material doesn't hold.