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Ohm's Law Equation:
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Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the current through a conductor between two points is directly proportional to the voltage across the two points.
The calculator uses the Ohm's Law equation:
Where:
Explanation: The equation shows that resistance equals voltage divided by current. This relationship helps determine the appropriate resistance needed for a circuit given specific voltage and current requirements.
Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate resistors, preventing component damage, and ensuring proper circuit operation. It helps engineers and technicians determine the right resistor values for voltage division, current limiting, and load matching applications.
Tips: Enter voltage in volts and current in amps. Both values must be positive numbers greater than zero. The calculator will compute the required resistance in ohms for your specific application.
Q1: What are the units for resistance calculation?
A: Resistance is measured in ohms (Ω), voltage in volts (V), and current in amperes (A).
Q2: Can I use this for AC circuits?
A: This calculator is primarily for DC circuits. For AC circuits with reactive components, impedance calculations are more appropriate.
Q3: What if I know resistance and want to find voltage or current?
A: Ohm's Law can be rearranged as V = I × R for voltage calculation or I = V / R for current calculation.
Q4: Are there limitations to Ohm's Law?
A: Ohm's Law applies to ohmic materials where resistance remains constant. It may not accurately describe non-ohmic components like diodes and transistors.
Q5: How do I select the right resistor after calculation?
A: Choose a standard resistor value closest to your calculation, considering power rating (P = I² × R) and tolerance requirements.