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?

wiseowl Nov 2, 2023

#1**-1 **

1

If we cut the wire in half, the resistance will also be halved. Therefore, the new resistance will be R/2.

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

Therefore, the new current will be:

I = V/(R/2) = 2V/R

We know that the original current was 25 milliamps, so the new current will be:

I = 2V/R = 2 * 175V / (25mA * 1000) = 14mA

Therefore, the new current is 14 milliamps.

parmen Nov 2, 2023