Hi all.

If I have a a bulb connected to a 3V battery how do I calculate how many C that has been passed through it, when it has used 30 J?

Thanks....hope I make sense.

Nicholas

 

Originally posted by AE35@Mar 2 2006, 01:03 AM
Hi all.

If I have a a bulb connected to a 3V battery how do I calculate how many C that has been passed through it, when it has used 30 J?

Thanks....hope I make sense.

Nicholas

[post=14534]Quoted post[/post]​

One volt equals one joule per coulomb. The rest is algebra: multiply both sides by C and divide both by volts.
V = J / C
C * V = J
C = J / v
C = 30J / 3v = 6.02x10^24 electrons.