Wire X has a resistance of 18 Ω. Wire Y is made of the same material and is at the same temperature. If Y is the same length as X, but 3 times the diameter, what is its resistance?
Answers
The electrical resistance of an electrical conductor is the opposition to the passage of an electric current through that conductor.The resistance of a wire is inversely proportional to the area of cross section of the wire. That is, the resistance of wire decreases as the diameter of the wire increases and the resistance of the wire increases as the diameter of the wire decreases.
Answer:
I’m not going to answer you question directly, but I will tell you how you can solve it yourself…
Remember that the total area of a wire cross-section is proportional to the square of the diameter. So a wire 3 times as wide as another should be 9 times the area.
Now, treat this wider cross section as though it is nine resistors wired up in parallel to replace the original 1 resistor. Each of these extra resistors can be modeled as being the same resistance as the original wire. Now use the resistance equation for a parallel set of NINE resistors to find the new resistance.