Question Video: Using Ohm’s Law to Calculate the Resistance of a Resistor in a Circuit with a Battery | Nagwa Question Video: Using Ohm’s Law to Calculate the Resistance of a Resistor in a Circuit with a Battery | Nagwa

# Question Video: Using Ohm’s Law to Calculate the Resistance of a Resistor in a Circuit with a Battery Science • Third Year of Preparatory School

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The diagram shows a circuit consisting of a battery and a resistor. What is the resistance of the resistor?

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### Video Transcript

The diagram shows a circuit consisting of a battery and a resistor. What is the resistance of the resistor?

In this question, we are given a diagram of an electric circuit that consists of a battery and a resistor. The battery provides a potential difference of 24 volts to the circuit and the current in the circuit is three amperes. We are asked to find the resistance of the resistor. In order to do this, we’re going to use Ohm’s law. Ohm’s law states that the potential difference across a component is equal to the current through the component multiplied by the electrical resistance of the component. As an equation, 𝑉 equals 𝐼 times 𝑅, where 𝑉 is the potential difference, 𝐼 is the current, and 𝑅 is the resistance.

In this question, we are concerned with finding the electrical resistance. So let’s rearrange this equation to get the resistance by itself on one side. We can do this by dividing both sides of the equation by the current 𝐼. These 𝐼-terms on the right-hand side cancel, giving us an equation for resistance. The resistance is equal to the potential difference divided by the current.

Now that we have the right equation, we can answer this question. The battery provides a potential difference of 24 volts to the resistor. So the potential difference across the resistor, 𝑉, is equal to 24 volts. The current through the resistor 𝐼 is three amperes. Let’s recall that electrical resistance is measured in units of ohms, which are represented by this symbol. With the values of 𝑉 and 𝐼 substituted into this equation, we see that the resistance of the resistor is equal to 24 volts divided by three amps, which is equal to eight ohms. This is the resistance of the resistor.

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