In an experiment, which variable is deliberately changed to observe its effect?

In an experiment, which variable is deliberately changed to observe its effect?

• A. Independent Variable
• B. Dependent Variable
• C. Control Variable
• D. Constant

Answer: (A)

The main idea is that the variable you change on purpose to see what happens is the independent variable. It is the input you control to test its effect on another outcome, often shown on the x-axis in graphs. For example, if you’re testing how different amounts of fertilizer affect how tall a plant grows, the amount of fertilizer is the independent variable. The thing you measure—the plant’s height or biomass—is the dependent variable, because it depends on how much fertilizer you gave. To make sure the results come from changing the independent variable and not some other factor, you keep other conditions the same. Those unchanged factors are the control variables. They provide a fair comparison so you can see the true effect of the independent variable. A constant is simply something that doesn’t change during the experiment; it’s what you maintain when you set up the control variables, not the factor you deliberately vary to test its effect.

The main idea is that the variable you change on purpose to see what happens is the independent variable. It is the input you control to test its effect on another outcome, often shown on the x-axis in graphs. For example, if you’re testing how different amounts of fertilizer affect how tall a plant grows, the amount of fertilizer is the independent variable. The thing you measure—the plant’s height or biomass—is the dependent variable, because it depends on how much fertilizer you gave.

To make sure the results come from changing the independent variable and not some other factor, you keep other conditions the same. Those unchanged factors are the control variables. They provide a fair comparison so you can see the true effect of the independent variable. A constant is simply something that doesn’t change during the experiment; it’s what you maintain when you set up the control variables, not the factor you deliberately vary to test its effect.