What happens when to CURRENT when the voltage doubles?

Question

what's the relationship between P V I ?

p(watts)

v(volts)

i(amps.)

What is the relationship, i can't figure it out, help me out here?

Answer 1

P = V*I

and

V = I*R

So also

P = (I^2)*R

P = (V^2) / R

Therefore, at a constant power, the current will halve when the voltage doubles.  But at a constant resistance, the current will double when the voltage doubles.

Answer 2

It depends upon other conditions too. I presume you are talking of a home appliance, whose load is specified. That is it has the resistance (or impedance same). Then current doubles; it draws double the current. If it doesn't burn then its power consumption (watts), the product of voltage and current each being double, gives rise to four times of power consumption. This all happens in same time interval, so your energy consumption will be four times (time being the same). Have you anything else ?(you haven't specified the conditions).  

Answer 3

Well, after sorting out the poor grammar, I guess that you are asking if the current and applied voltage move together, and they do not. The others sort of "muddied" your "water". With a fixed resistance, if the voltage goes up, as in your question it is doubled, then current goes down. I really doubt that your book is that poorly written.

For the P,V and I thing, P stands for power, that is, watts. V stands for volts. Usually, so does "E". "E" actually means "electromotive force", but that is commonly termed "volts". "E" and "V" are used interchangeably. Just accept it, don't try to rearrange it. These are conventions that are older than I am, and I am 56 years old. "I" stands for current, or amps, and any smaller variation there of. In the parlance of of electricity, small letters stand for fractions of a unit, while capital letters stand for whole units. Such as 1 mA means 1 milli-Amp, or 0.001 Amps. If you are going to learn electricity, you need to learn the nomenclature and what the symbols and letters mean. I have, however, digressed.

P = E multiplied by I, (E x I = P). 12 volts multiplied by 10 "I", (amps) = 120 watts. It really is just that simple.

Answer 4

Current doubles, Power (watts) quadruples.

E = I * R so if R remains same 2E requires 2I for equality.

Power is I * E, so if both  double, power quads.