Answer
(a) Bright
(b) Dark
(c) Dim
Work Step by Step
(a) Potassium chloride ($KCl$) is an ionic compound, which is very dissociated in water. Therefore, the solution will be very bright and conductive.
(b) Methanol is a very molecular compound, which makes it a bad conductor in water.
(c) Acetic acid $(CH_3CO_2H)$ is a weak electrolyte (according to the table 4.1, Page 118); therefore, the light bulb will only receive part of the electricity.
