Physics 2010 JAMB Past Questions - Question 14: A hydrometer is an instrument used in measuring

Correct Answer

A

Explanation

A hydrometer is an instrument used to measure the density or specific gravity of a liquid. It is commonly used in various applications, including:

1. Brewing and Winemaking: Hydrometers are used to measure the specific gravity of fermenting liquids like beer and wine. This helps brewers and winemakers track the progress of fermentation and estimate alcohol content.

2. Laboratory Analysis: In scientific laboratories, hydrometers are used to determine the density of various liquids, which can be important for chemical analysis and research.

3. Oil and Petroleum Industry: Hydrometers are used to measure the specific gravity of oil and other petroleum products. This information is vital for assessing the quality and composition of crude oil and its derivatives.

4. Battery Testing: In the automotive industry, hydrometers are used to check the specific gravity of electrolyte solutions in lead-acid batteries, helping to assess battery health and charge status.

5. Soil Testing: Soil scientists use hydrometers to determine the particle size distribution and density of soil samples, which is essential for soil classification and engineering purposes.

6. Water Quality Testing: Hydrometers are used to assess the salinity and density of water in environmental studies and in monitoring water quality in aquariums and aquatic systems.

Hydrometers work on the principle of buoyancy. The hydrometer is a sealed, elongated glass tube with a weighted bulb at the bottom. When it is placed in a liquid, the depth to which it sinks depends on the liquid's density. By reading the scale on the hydrometer, one can determine the specific gravity or density of the liquid being tested. Different hydrometers are designed for specific applications, so they may have varying scales and measurement ranges.

In summary, a hydrometer is a versatile instrument used to measure the density or specific gravity of liquids, making it valuable in a wide range of industries and scientific fields.