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Mission EC4 Resistance, Voltage and Current

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Hold down the T key for 3 seconds to activate the audio accessibility mode, at which point you can click the K key to pause and resume audio. Useful for the Check Your Understanding and See Answers.

The Question

If the resistance of a circuit is doubled, then the current through the circuit would be ____.

Formula Fix

The current (I) in a circuit is dependent upon the electric potential difference (i.e., voltage or ∆V) impressed across the circuit and the overall resistance (R) of the circuit. The equation that expresses this relationship is:
 
I = ∆V / R.

Math Magic

Equations serve as useful guides to thinking about how an alteration in one variable would affect another variable. An inspection of the current equation in the Formula Frenzy section reveals the dependency of current on voltage and resistance. The equation shows that the current in a circuit is inversely proportional to the resistance of the circuit. An increase in resistance would result in a decrease in current. And the factor by which the resistance increases is the same factor by which the current decreases. So if the resistance becomes 10 times greater, the current would become 1/10th of its original value.

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