Question

One of the following apparatus is used to determine particle size by the gravity sedimentation method

• A. Pyknometer
• B. Ostwalds viscometer
• C. Anderson apparatus
• D. Friabilator

Answer 1

The Correct Option is C

The question asks us to identify which apparatus is used to determine particle size through the gravity sedimentation method. Let's explore the options provided:

1. Pyknometer: This is an instrument used to measure the density or specific gravity of liquids. It is not related to measuring particle size by gravity sedimentation methods.
2. Ostwald's viscometer: This instrument is used to measure the viscosity of a liquid using the flow time of a specific volume under gravity. Again, it is not used for particle size determination through gravity sedimentation.
3. Anderson apparatus: This device is specifically used for determining particle size distribution based on gravitational sedimentation. It measures how particles settle under the influence of gravity, making it directly relevant for the gravity sedimentation method of particle size analysis.
4. Friabilator: This instrument is used to test the friability of tablets, i.e., their ability to resist abrasion. It is unrelated to particle size measurement.

Based on this analysis, the Anderson apparatus is the only option that is used for determining particle size by the gravity sedimentation method. This makes it the correct answer.

Understanding this selection involves recognizing that gravity sedimentation methods involve observing the settling rates of particles in a fluid, influenced by gravity, and the Anderson apparatus is designed for these specific measurements.