In physics, Ohm's law says that current through a wire, $I$, is directly proportional to voltage, $V$, and inversely proportional to resistance, $R$:

\[I=\frac{V}{R}.\]

It's also true that resistance is directly proportional to the length of the wire. We have a piece of wire. We pass $50$ volts through this wire and measure $200$ milliamps of current. If I cut the wire in half and pass $300$ volts through it, how many milliamps of current will I measure?

angelxbobaa Jun 10, 2021

#2**+3 **

Re-arranging:

V/I = R

50 v / .2 A = 250 ohms

Now cut wire in half it i s now 125 ohms

apply 300 v across it (NOTE: the question erroneously says ' 300 volts THROUGH it ' )

I = v/R = 300/125 = 1.2 Amps or 1200 milliamps

Guest Jun 10, 2021

#4**0 **

Here is my answer:

I don't understand electricity. This is based solely on the info given.

\(I=\frac{V}{R}\\ R\propto L\\ I=\frac{V}{kL}\\ find\;\;k\\ When \;\;V=50\;\;I=200,\;\;L=2\\ 200=\frac{50}{2k}\\ k=0.125\\so\\ I=\frac{V}{0.125L}\\~\\ Find\; I\;\;when\;V=300\;and\;L=1\\ I=\frac{300}{0.125*1}\\ I=2400\;milliamps \)

LaTex:

I=\frac{V}{R}\\

R\propto L\\

I=\frac{V}{kL}\\

find\;\;k\\

When \;\;V=50\;\;I=200,\;\;L=2\\

200=\frac{50}{2k}\\

k=0.125\\so\\

I=\frac{V}{0.125L}\\~\\

Find\; I\;\;when\;V=300\;and\;L=1\\

I=\frac{300}{0.125*1}\\

I=2400\;milliamps

Melody Jun 15, 2021