A student builds a circuit to investigate the resistance of component X.

What is the name of this circuit component?

Why is this component needed in this circuit?
The student uses the circuit to take current and potential difference readings. The student plots a graph of the results.

Look at the graph. What is component X in the circuit?
The resistance of component X varies as the potential difference changes. Describe how the graph shows this and explain why this happens.
Component X has a resistance of 24 Ω24\ \Omega24 Ω when a current of 0.5 A0.5\text{ A}0.5 A flows.
Calculate the potential difference across component X. Use the equation: Potential difference=Current×Resistance\text{Potential difference} = \text{Current} \times \text{Resistance}Potential difference=Current×Resistance
Component X has a resistance of 24 Ω24\ \Omega24 Ω when a current of 0.5 A0.5\text{ A}0.5 A flows.
Calculate the power of component X when a current of 0.5 A0.5\text{ A}0.5 A flows.