Question

Given alongside is the diagram of an experimental set-up to demonstrate a certain phenomenon in plants.

What is the purpose of the spring balance in the set-up?

Answer 1

The spring balance progressively measures the change in weight of the set-up. This is because as the plant transpires, it creates a suction force in the plant which allows roots to absorb more water from the test tube. Hence, the water in the test will get reduced. Thus, the weight of the entire set will decrease.