Answer:
Manipulated/independent variable- DIFFERENT ELECTROLYTES
Responding/dependent variable- BRIGHTNESS OF BULB
Controlled variable- WET CELL
Explanation:
The independent variable, also known as manipulated variable is the variable that the experimenter changes or manipulates in an experiment. In this case where different electrolytes are observed to see which will light a bulb most brightly, the manipulated variable is the DIFFERENT ELECTROLYTES.
Dependent or responding variable is the variable of an experiment that responds to the changes made to the independent variable. It is the variable that is being measured in an experiment. In this case, the BRIGHTNESS OF BULB is dependent on the electrolyte used, hence, it is the responding variable.
Controlled variable or constant is the variable that the experimenter keeps the same throughout the experiment. In this case, the WET CELL is kept constant for all the electrolytes used i.e. it is not changed, hence, the WET CELL is the controlled variable.
