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# Help with Resistance formula. Answered

How to find the voltage after adding a resistor with the resistance formula? For example I have a circuit that uses 0.975A and I add a 1000ohm resistor to it, if its powered by 220v main then according to V=IR what should be the voltage drop due to the resistor?

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V=IR
It would depend series or parallel.
Parallel that resistor and that voltage it would be 0.22 A and 220 volt drop across the resistor.

in series it would be along the lines described by icing so it would be IR=V or
0.179 x 1000 = 179 volts drop across the resistor.
and
0.179 x 226 = 41 volts drop across the circuit.

These numbers are rounded.

Joe

RAC = V/I = 220/o.975 = 226 Ohms Impedance

Sounds like a Power Toaster

Now you add 1000 more ohms for a total of 1226 ohms

New AC Current = V/R = 220 / 1226 = o.179A

You need to know 2 of the 3 variables - Voltage - Resistance - Current. Then you can calculate the third.

Volts= Current x Resistance

V=Volts
I=Current (amps)
R = resistance (ohms)

V=I x R
so
I=V/R
or
R=V/I