Question

a student examines the effect of the number of d batteries in a closed circuit on the brightness of a light bulb. in the experiment, four circuits were built with 1, 2, 3, and 4 batteries respectively. for each trial, the brightness of the light bulb was measured using a light meter. which variable should the student keep constant? the type of batteries the brightness of the light bulb the data collected from the light meter the number of batteries

Explanation:

In a scientific experiment to test the effect of the number of batteries on bulb - brightness, variables other than the independent variable (number of batteries) and dependent variable (bulb - brightness) should be controlled. The type of batteries is a potential confounding variable that needs to be kept constant to ensure valid results. The brightness of the light bulb is the dependent variable, data from the light meter is the measured result, and the number of batteries is the independent variable.

Answer:

the type of batteries