Physics 2009 JAMB Past Questions - Question 18: The thermometer whose reading is indicated by a change in color of its

Correct Answer

D

Explanation

The type of thermometer that changes color to indicate a temperature reading is commonly known as a "color-changing thermometer" or a "liquid crystal thermometer." These thermometers contain special liquid crystals that respond to temperature changes by changing colors. The color transition is a result of the liquid crystals' unique properties, which alter their molecular structure based on temperature variations. As the temperature changes, the liquid crystals change color in a predictable manner, allowing users to estimate the temperature based on the observed color.

These thermometers are often used for quick and easy temperature assessments in various applications, such as in aquariums, on beverage containers, and as forehead or fever thermometers. The color-changing feature makes them user-friendly and suitable for situations where a numerical temperature reading is not necessary, and a visual indicator suffices.