Karma connected a dry cell to a bulb using a few pieces of wire and lit the bulb. He was curious to know how the thickness of the used wire affects the life span of a dry cell. In this test, find out the independent variable, dependent variable, and controlled variable.

Question

Accepted Answer

Independent variable: Thickness of the connecting wire (Karma deliberately changes this). Dependent variable: Life span of the dry cell (this is measured/observed and depends on wire thickness). Controlled variable: Type/rating of the bulb, type and charge of the dry cell, length of the wire, and the material of the wire — these must be kept the same in every trial so only wire thickness affects the result.