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?
+8 Let's first find the resistance of the wire using Ohm's formula:
R = V/I = 60/0.2 = 300 ohm
Now, if we cut the wire in half, its length will be halved, which means that the resistance will also be halved:
R/2 = 300/2 = 150 ohm
Now we can find the current that will flow through half the wire at 400 volts, again using Ohm's formula:
I = V/R = 400/150 = 2.67 amps
In milliamps, this would be:
I = 2.67 * 1000 = 2670 milliamps
Answer: At 400 volts, 2670 milliamps of current will flow through half of the wire.
