+25 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?
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
+118667 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
