Question

An experiment is designed to test what color of light will activate a photoelectric cell the best. The photocell is set in a circuit that "clicks" in response to current. The faster the current, the more clicks per minute. In this experiment, the number of clicks in one minute is recorded for each color of light shining on the photocell. To change the color of light, a different color of cellophane is placed over the same flashlight and the flashlight is then located a specific distance from the photocell.
In the above experiment, which factor is the independent variable?
A)the number of clicks
B)the color of the light
C)the original source of the light
D)the photocell

Answer 1

The independent variable is the one we control changes in, which is B) the color of the light. The number of clicks (A) is the dependent variable, which we are measuring. The original source of the light (C) is something we control, but we do not change anything in it. Finally, the photocell (D) is just part of the setup, and we also do not change anything about it.