The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V,60 Hz outlet.

-What is the resistance of the iron?

Question

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V,60 Hz outlet.
 
-What is the resistance of the iron?

Quizplus · Accepted Answer

The resistance of the iron can be found using Ohm's Law, which states that V=IR where V is the voltage, I is the current, and R is the resistance. 
From the graph, we can see that the maximum current is around 7.1 amps. Using Ohm's Law, we can calculate the resistance as R=V/I, where V is 120 volts and I is 7.1 amps. 
R = 120/7.1 = 16.9 ohms 
Therefore, the best choice is C, which is the closest value to 16.9 ohms.

The Figure Shows Variation of the Current Through the Heating