Physics (AS & A Level) · May / June 2026 · Paper 12 · Question 13

A hydrometer is a device for measuring the density of liquids. It consists of a weighted bulb at the bottom of a calibrated tube. The hydrometer is floating in a liquid at room temperature. The length of the tube above the level of the liquid is h. Which change causes h to decrease?

1. Aadding more liquid into the cylinder
2. Bdecreasing the density of the liquid
3. Cincreasing the air pressure above the liquid
4. Dincreasing the density of the liquid

As printed in the paper