# ELECTRONICS: Finding the voltage?

Given:

P=100 watts
R=100 ohms

Find: Voltage

Kindly show all necessary and important solutions. Really need it. Thanks.

Answer:
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. R can be calculated.
R = V / I

P = VI (P is Watts, V is voltage and I is Amps/current) basically we need more details.

For single phase divide your watts by the voltage to get amps. You'll find on your residential system that the 220 volt heater will draw 1/2 the amps that the 110 volt heater will at the same watts. Depending on the total watts used the 220 volt unit will allow you to go a size smaller on the circuit conductors.
If your concerned about voltage drop for a residential circuit, don't be unless it is an exceptionally long run. If you are concerned then consult any electrical formula book or put "voltage drop" in a google search engine. Hope this helps.
This is easy as PIE> P=I*E
P=I^2 * R, SQRT (100/100) = 1 amp
so P/1= 100 volts
ohms law baby

V = 100
Ohms law Power = V x I but V = I x R so power = I x I x R 100 = 100 X Ix I therefore
I = 1 ampere. V = 100
Power is also = V x V/R = 100 = V X V/100
Therefore v= 100
Start with Ohms Law: V = IR.

Let's solve for I ...

I = V/R.

Now, power is equal to voltage times current, or

P=VI

Let's substitute (V/R) for I, and we get

P = V*(V/R), which is V²/R.

We can use this with the above parameters:

100 Watts = V²/(100 ohms)

V² = 10000, so V = 100 V.

I hope this was helpful.
The relationship between power voltage and resistance can be summarized in the formula P = V^2/R(where V^2 means V squared, V being voltage P being power and R being resistance). This is derived from P=VI and I=V/R which is a power equation and ohms law. Subsituting in your values of P=100 and R=100 you get

100=V^2/100

with algebra 100*100=V^2

take square root of both sides(more algebra)to get

V=100 volts
1 volt

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