Question Video: Recalling How the Current through a Resistor Changes When the Potential Difference across It Doubles | Nagwa Question Video: Recalling How the Current through a Resistor Changes When the Potential Difference across It Doubles | Nagwa

# Question Video: Recalling How the Current through a Resistor Changes When the Potential Difference across It Doubles Science • Third Year of Preparatory School

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Complete the following sentence: If the potential difference across a resistor doubles, the current through it ＿.

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### Video Transcript

Complete the following sentence. If the potential difference across a resistor doubles, the current through it blank.

Here, we’re asked to complete the sentence by filling in the blank. We’re asked how the current will change through a resistor with constant resistance if the potential difference across the resistor doubles.

Let’s begin by looking at Ohm’s law, the expression we need to figure out the right answer. Ohm’s law states for two points in a circuit, the potential difference across the points equals the current between the points multiplied by the resistance of the object between the points. Ohm’s law can be written as an equation, where 𝑉 stands for the potential difference across the resistor, 𝐼 stands for the current in the resistor, and 𝑅 stands for the resistance of the resistor.

Because we are interested in what would happen to the current, we must make current 𝐼 the subject of the equation. We can do this by dividing both sides of the equation by the resistance. This gives us the equation current 𝐼 is equal to the potential difference 𝑉 divided by the resistance 𝑅.

Since the resistor has a constant resistance, Ohm’s law is telling us that the potential difference is proportional to the current. This means that if the potential difference is doubled to two times 𝑉, then the current must also be doubled to two times 𝐼. Therefore, the correct answer to complete this sentence is “doubles.” If the potential difference across a resistor doubles, the current through it doubles.

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