I need help with this
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 60 volts through this wire and measure 200 milliamps of current. If I cut the wire in half and pass 400 volts through it, how many milliamps of current will I measure?
200 milliamps ==200 / 1000 =0.2 amps.
R==60 / 0.2 ==300 ohms.
300 / 2 ==150 ohms - resistance in 1/2 of original wire.
I==400 / 150 ==2.67 amps.
2.67 x 1,000 ==2,670 milliamps of current.
Cutting the wire in half will increase the amps by a factor of 2 to 400 ma (because the resistance is halved)
increasing the voltage ACROSS the wire will increase the amps by 400 / 60
400 / 60 * 400 ma = 2666.7 mAmps