ANS:A - more than

In a rotameter, the density of the float material is less than that of the liquid it displaces. Here's an explanation:

• Rotameter: A rotameter is a device used to measure the flow rate of a fluid in a closed tube. It typically consists of a tapered tube and a float that moves up and down inside the tube based on the flow rate of the fluid.
• Float Material: The float inside the rotameter is designed to have a density less than that of the fluid it displaces. This ensures that the float can rise or fall freely based on the flow rate of the fluid. If the float were denser than the fluid, it would sink to the bottom of the tube, making it unsuitable for measuring flow rate.