Solve the variation problem.
-If the voltage, V, in an electric circuit is held constant, the current, I, is inversely proportional to the resistance, R. If the current is 240 milliamperes when the resistance is 3 ohms, find the current when the resistance is 18 ohms.
A)1434 milliamperes
B)120 milliamperes
C)40 milliamperes
D)1440 milliamperes

Question

Quizplus · Accepted Answer

Since the current is inversely proportional to the resistance, we use the formula $I_1R_1 = I_2R_2$. Given $I_1 = 240$ milliamperes and $R_1 = 3$ ohms, when $R_2 = 18$ ohms, we find $I_2$ by $240 \times 3 = I_2 \times 18$. Solving for $I_2$ gives $I_2 = 40$ milliamperes.

Solve the Variation Problem