I know that this has to be an easy problem, but my teacher left us in December and we got stuck with an idiot who hasn't taught us anything since then......(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

How many 65-W light bulbs can be connected in parallel across a potential difference of 85V before the total current in the circuit exceeds 2.1 A?

2. Relevant equations

[tex]\Sigma[/tex]1[tex]/[/tex]Req=1[tex]/R1[/tex]+1[tex]/R2[/tex]+1[tex]/R3[/tex]...

P=IV

V=IR

3. The attempt at a solution

I can't get an answer that makes any sense, but this is what I tried to do.

P=65-W

V=?

I=2.1A

P=IV

65=(2.1A)V

30.95V=V

R=14.738[tex]\Omega[/tex]

X= number of bulbs

[tex]\epsilon[/tex]= I((1/R)X)^-1

85V= (2.1A)(1/14[tex]\Omega[/tex])X)^-1

(14[tex]\Omega[/tex]/X)(2.1A)=85V

29.4V/X=85V

29.4V=(85V)X

.34588=X

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# Homework Help: 65W bulbs connected in parallel (hopefully easy)

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