Which of these describes a control variable?
A) The variable that changes as a result of the experiment’s manipulation.
B) The variable that is intentionally kept constant and unchanged throughout the experiment.
C) The variable that is measured and recorded to collect data.
D) The variable that is manipulated or changed intentionally to observe its effect.
Correct Answer:
B) The variable that is intentionally kept constant and unchanged throughout the experiment.
Explanation:
A control variable, also known as a constant, is a variable that remains unchanged and consistent during a scientific experiment. Its purpose is to provide a baseline for comparison with the variable being manipulated (independent variable) and the variable being measured (dependent variable). Options A, C, and D describe other types of variables in an experiment, but option B specifically defines the role of a control variable.
