Question

You are doing an experiment about the diet of mice. You want to see how the amount of salt in a mouse's food affects how much water the mouse drinks. What should the independent variable be?
a. the type of mouse
b. the amount of salt in the food
c. the type of cage the mouse is in
d. the amount of water the mouse drinks

Answer 1

A variable, which is controlled or changed in a scientific experiment to examine the influences on the dependent variable is known as an independent variable. On the other hand, a dependent variable refers to the variable, which is being measured and tested in a scientific experiment.  

In the given case, one is observing that how the amount of salt in a mouse food influences the water the mouse drinks. Thus, the amount of salt in the food in the given case is an independent variable, as one can determine the amount of water consumed by the mouse, by manipulating the amount of salt intake given to the mouse.  

Hence, the correct answer is option B.