These calculators perform calculations associated
with power (wattage). The bottom one calculates power dissipated in a resistor given the
current flowing through it.
Calculate Power from Voltage & Current (P = V * I):
Calculate Voltage from Power & Current (V = P / I):
Calculate Current from Power & Voltage (I = P / V):
Calculate Power Dissipated in a Resistor (P = I2 * R):
The formula for calculating power in DC circuits is:
P = V * I, where P is power in Watts, V is voltage in Volts and I is current in Amps
This can be re-arranged to give:
V = P / I
I = P / V
Combining this equation with Ohms Law gives the power dissipated in a resistor:
P = V * I
V = I * R (Ohms Law)
Combining these gives P = I * I * R
or P= I2
for more details.
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