Question

what is the effect of changing the length of a piece of copper wire on its resistance? resistance of the wire is the variable in this experiment.

Explanation:

Step1: Recall resistance formula

The resistance formula is $R =
ho\frac{l}{A}$, where $R$ is resistance, $
ho$ is resistivity (constant for a given material like copper), $l$ is length and $A$ is cross - sectional area.

Step2: Analyze length - resistance relationship

From the formula, when the cross - sectional area $A$ and resistivity $
ho$ are constant, resistance $R$ is directly proportional to the length $l$ of the wire. So, increasing the length of the copper wire increases its resistance and decreasing the length decreases its resistance.

Step3: Identify variable type

In an experiment where we are looking at the effect of changing the length of the wire on its resistance, the resistance is the dependent variable because its value depends on the length of the wire (the independent variable).

Answer:

Dependent