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Anonymous Poster

Electricity

06/10/2008 9:29 AM

I have a question that if there is a bulb of 12v and 3A (36w)

and if we give 3v and 12A to that bulb, is it work..?

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Guru
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#1

Re: Electricity

06/10/2008 9:47 AM

No. Because the resistance of the bulb is way too high to draw that much current at 3 volts.

Remember the equation I = E/R

Current = Volts / Resistance

Resistance of the bulb is the fixed component here at 4 Ω. So, the only way you can increase current is to increase voltage. Lowering the voltage will decrease the current.

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#2

Re: Electricity

06/10/2008 9:56 AM

You can't just swap quantities around willy nilly...

Do you think your car would run if you swapped the fuel/air ratio round the other way?

Or maybe you add a pinch of salt to a cup of rice when cooking...try that round the other way....

Del

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#3

Re: Electricity

06/10/2008 11:28 AM

Like a car headlight bulb?

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Power-User
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#4

Re: Electricity

06/11/2008 8:25 AM

First you wouldn't be able to give the poor little bulb 12 A unless you injected it with a hat box. Not enough load.

Don't confuse Power with the components that make it up.

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#5

Re: Electricity

06/11/2008 2:46 PM

Even if you ignore Ohm's Law, the current carrying capacity of the wiring almost certainly could not support the amperage.

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