+1729 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 = 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 $500$ volts through this wire and measure $25$ milliamps of current. If I cut the wire in half and pass $175$ volts through it, how many milliamps of current will I measure?
+15075
If I cut the wire in half and pass $175$ volts through it, how many milliamps of current will I measure?
R=VI=500V25⋅10−3AR=20kΩ
The resistance of the two halves of the wire in combination is R2=20kΩ4=5kΩ.
I=VR2=175V5⋅103Ω⋅103mAAI=35mA
The current of the two halves of the wire in combination is 35mA.
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