Ohm's law - calculator and ohms formulas - voltage current resistance formula - magic triangle equation tip online voltage volts resitor resistance amps amperes audio engineering E V I R - sengpielaudio Checker
 
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Ohm's law - calculator and formulas

Resistance (ohms), current (amps), and voltage (volts)

Input:
resistance R
 ×
ohms

current I

amperes

Output:
voltage V

volts

 
 
voltage V
 
volts
resistance R

ohms
current I

amperes
 
 
voltage V
 
volts
current I

amperes
resistance R

ohms
 
= reset.

V = R × I         I = V / R         R = V / I

The formulas of Ohm's Law

Ohm's Law can be rewritten in three ways for calculating current, resistance, and voltage.
If a current I should flow through a resistor R, the voltage V can be calculated.
V = R × I

If there is a voltage V across a resistor R, a current I flows through it. I can be calculated.
I = V / R

If a current I flows through a resistor, and there is a voltage V across the resistor R can be calculated.
R = V / I

 Name    Formula sign   Unit   Symbol  
 voltage  V or E volt V
 current  I  ampere (amp)   A
 resistance  R ohm Ω
 power  P watt W

The magic triangle  Tip: Ohm's magic triangle

The magic V I R-triangle can be used to calculate all formulations of ohm's law.
Use a finger to hide the value to be calculated. The other two values then show
how to do the calculation.

The symbol I or J = Latin: influare, international ampere, and R = resistance. V = voltage,
electric potential difference, also called voltage drop, or E = electro motive force (EMF = voltage).

If you need the unit of power P = V × I look for the
Red Power Dot Big Power Formulas:
Calculations: power, voltage, current, resistance, and power

Some are of the opinion that Georg Simon Ohm calculated the "specific resistance".
Therefore they believe that only this can be the true ohm's law.

  Value of the Resistance  
 
Formel
 
R  = Resistance Ω
ρ  = Electrical resistivity   Ω·m
l  = Length m
A  = Cross-sectional area m2

Electrical conductivity = σ = 1/ρ
Electrical resistivity ρ = 1/σ

Cross-sectional area - cross section - slice plane

Now there is the question:
How can you calculate the cross sectional area (slice plane) A
from the wire diameter d and vice versa?

Calculation of the cross section A (slice plane) from diameter d:
Formula calculation diameter
r = radius of the wire
d = diameter of the wire

Calculation diameter d from cross section A (slice plane):
Formel Berechnung Durchmesser aus Querschnitt
Cross section A of the wire in mm2 inserted in this formula gives the diameter d in mm.

Calculation − Round cables and wires:
• Diameter to cross section and vice versa •

Electrical voltage V = I × R      (Ohm's law)

Electrical voltage = amperage × resistance

Please enter two values, the third value will be calculated.

Electrical voltage V volts Magic triangle volt
Amperage I amps
Resistance R ohms

Electric power P = V × I      (Power law)

Electric power = voltage × amperage

Please enter two values, the third value will be calculated.

Electric Power P watts Magic triangle power
Voltage V volts
Amperage I amps

Ohm's law. V = I × R, where V is the potential across a circuit element, I is the current
through it, and R is its resistance. This is not a generally applicable definition of
resistance. It is only applicable to ohmic resistors, those whose resistance R is
constant over the range of interest and V obeys a strictly linear relation to I. Materials
are said to be ohmic when V depends linearly on R. Metals are ohmic so long as one
holds their temperature constant. But changing the temperature of a metal changes R
slightly. When the current changes rapidly, as when turning on a lamp, or when using AC
sources, slightly non-linear and non-ohmic behavior can be observed. For non-ohmic
resistors, R is current-dependent and the definition R = dV/dI is far more useful. This is
sometimes called the dynamic resistance. Solid state devices such as thermistors are
non-ohmic and non-linear. A thermistor's resistance decreases as it warms up, so its
dynamic resistance is negative. Tunnel diodes and some electrochemical processes
have a complicated I to V curve with a negative resistance region of operation. The
dependence of resistance on current is partly due to the change in the device's
temperature with increasing current, but other subtle processes also contribute to
change in resistance in solid state devices.

Calculation: Parallel Resistance (Resistor) Calculator

Color Code Calculator for Resistors

In acoustics we use ohm's law as acoustic equivalent

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