Question 44840
The electrical resistance R of a wire varies directly as its length L and inversely as the square of its diameter 'd'.
{{{Rd^2/L}}}
A wire 20 meters long and 0.6 centimeters in diameter made from a certain alloy has a resistance of 36 ohms.
{{{36(0.6)^2/20}}}
{{{0.648}}}
What is the resistance of a piece of wire 60 meters long and 1.2 centimeter in diameter made from the same material?
{{{Rd^2/L = 0.648}}}
{{{R = 0.648*60/(1.2)^2}}}
{{{R = 27}}}