In frequency modulation, which wave property remains constant?

The correct answer is - Amplitude.

Explanation:

Frequency modulation is a method or procedure that sends or transmits the signals such as radio broadcasting, telecommunication where the value of the transmitted signal is provided by the frequency of a high-frequency wave that carries the signal.

In this method of encoding the information, the amplitude of the carrier remains the same or constant but frequency varies in accordance with the modulating signal.

dynamic equilibrium is the answer.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.