Solve.
-At a fixed temperature, the resistance R of a wire varies directly as the length l and inversely as the square of its diameter d. If the resistance is 0.4 ohm when the diameter is 1 mm and the length is 200 cm, what is the
Resistance when the diameter is 2 mm and the length is 1620 cm?
A)1.62 ohm
B)162 ohm
C)0.81 ohm
D)405 ohm

Question

Quizplus · Accepted Answer

The resistance R is given by R = k * (l/d^2). First, find k using the initial conditions: 0.4 = k * (200/1^2), so k = 0.002. Then, use this k to find the new resistance: R = 0.002 * (1620/2^2) = 0.81 ohm.

Solve. -At a Fixed Temperature, the Resistance R of a Wire