Understanding Variables in Experiments

Which of the following best describes the role of an independent variable in an experiment?

• It is the variable that is measured or observed.

• It is the variable that is manipulated or changed by the researcher.

• It is the variable that remains constant throughout the experiment.

• It is the variable that is used to calculate the results.

In a study examining the effect of sunlight on plant growth, which of the following is the dependent variable?

• The amount of water given to the plants.

• The type of soil used.

• The height of the plants.

• The amount of sunlight received.

Tags

NGSS.MS-LS1-5

If a researcher is studying the impact of different fertilizers on crop yield, what is the independent variable?

• The type of fertilizer used.

• The amount of water the crops receive.

• The yield of the crops.

• The type of crops grown.

Tags

NGSS.MS-LS2-1

In an experiment to determine how temperature affects the solubility of a substance, what is the dependent variable?

• The temperature of the solution.

• The amount of substance dissolved.

• The type of substance used.

• The volume of the solution.

Tags

NGSS.MS-PS1-4

Which of the following scenarios correctly identifies the independent and dependent variables: "A scientist is testing the effect of different amounts of caffeine on heart rate"?

• Independent: Heart rate; Dependent: Amount of caffeine.

• Independent: Amount of caffeine; Dependent: Heart rate.

• Independent: Type of caffeine; Dependent: Heart rate.

• Independent: Heart rate; Dependent: Type of caffeine.

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

In a physics experiment, a student is investigating how the angle of a ramp affects the speed of a rolling ball. What is the dependent variable?

• The angle of the ramp.

• The speed of the ball.

• The mass of the ball.

• The length of the ramp.

A biologist is studying the effect of pH levels on the growth rate of bacteria. What is the independent variable in this study?

• The growth rate of bacteria.

• The type of bacteria.

• The pH level of the environment.

• The temperature of the environment.

Tags

NGSS.MS-LS1-5

In a chemistry experiment, a student is testing how the concentration of a reactant affects the rate of a chemical reaction. Identify the dependent variable.

• The concentration of the reactant.

• The rate of the chemical reaction.

• The temperature of the reaction.

• The volume of the reactant.

Tags

NGSS.HS-PS1-5

A psychologist is researching the impact of sleep duration on cognitive performance. What is the dependent variable in this research?

• The amount of sleep participants get.

• The cognitive performance of participants.

• The age of participants.

• The type of cognitive tests used.

In a study to determine how different types of music affect concentration levels, what is the independent variable?

• The concentration levels of participants.

• The type of music played.

• The duration of the music session.

• The age of participants.