📊 Calculated Voltage
0 V
V = I × R = 2A × 110Ω = 220 Volts
📖 What is Voltage?
Voltage (measured in Volts, symbol V) is the electrical potential difference that pushes electric current through a circuit. Named after Italian physicist Alessandro Volta (1745-1827), inventor of the electric battery. One volt is defined as the potential difference that drives one ampere of current against one ohm of resistance.
⚡ Ohm's Law Explained
V = I × R | I = V / R | R = V / I
Also: P = V × I | V = P / I | I = P / V
Also: P = V × I | V = P / I | I = P / V
📊 Common Voltage Reference Table
| Device / Application | Typical Voltage | Current | Power |
|---|---|---|---|
| Household Outlet (India) | 220-240V AC | 5-15A | 1100-3600W |
| USB Charger | 5V DC | 1-3A | 5-15W |
| Car Battery | 12V DC | 30-100A | 360-1200W |
| LED Bulb | 12V / 220V | 0.1-0.5A | 5-15W |
| Laptop Adapter | 19V DC | 3-5A | 45-90W |
| Mobile Phone Battery | 3.7V DC | 1-2A | 3.7-7.4W |
💡 How to Use This Voltage Calculator
- Method 1 (V = I × R): Enter current in Amperes (A) and resistance in Ohms (Ω)
- Method 2 (V = P / I): Enter power in Watts (W) and current in Amperes (A)
- Use preset buttons for common electrical values
- Results update in real-time as you type
- Use for DC circuits; for AC circuits, use RMS values
🔧 Practical Applications
- Household Circuits: India uses 220V AC - ensure appliances match this rating
- Car Electronics: 12V DC - check voltage before connecting devices
- USB Devices: 5V DC - all USB chargers provide standard 5V
📝 What is Voltage Drop?
Voltage drop is the reduction in voltage along a wire or circuit due to resistance. It's calculated using: V_drop = I × R_wire. For long cable runs, keep voltage drop under 3-5% for efficient operation.
⚡ Ohm's Law Triangle
V = I × R | I = V / R | R = V / I
V = I × R | I = V / R | R = V / I
📝 Frequently Asked Questions
❓ What is Ohm's Law? ▼
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The formula is V = I × R, where V is voltage (volts), I is current (amperes), and R is resistance (ohms).
❓ How do I calculate voltage using Ohm's Law? ▼
To calculate voltage, multiply current (in Amperes) by resistance (in Ohms): V = I × R. For example, 2 Amps × 110 Ohms = 220 Volts. Alternatively, if you know power and current, use V = P / I.
❓ What is the difference between AC and DC voltage? ▼
AC (Alternating Current) voltage changes direction periodically (like household outlets). DC (Direct Current) voltage flows constantly in one direction (like batteries). Both follow Ohm's Law for basic calculations.
❓ What is the standard household voltage in different countries? ▼
India, UK, Europe, Australia: 220-240V AC at 50Hz. USA, Canada, Japan: 110-120V AC at 60Hz. Most modern electronic devices support both voltages (100-240V).
❓ How to measure voltage in a circuit? ▼
Use a multimeter set to voltage (V) mode. For DC voltage, connect red probe to positive and black to negative. For AC voltage, connect probes across the terminals. Never measure high voltage without proper training.
💡 Educational Note: Voltage is named after Italian physicist Alessandro Volta (1745-1827), who invented the first electric battery. One volt is defined as the potential difference that drives one ampere of current against one ohm of resistance.
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