To minimize parallax error when reading the volume of a liquid in a graduated cylinder, where should you view the meniscus?

• A. From the top
• B. From the bottom
• C. At eye level
• D. From the side

Answer: (C)

Parallax error happens when your eye is not aligned with the measurement marks, so the perceived height of the liquid shifts with your viewing angle. The way to minimize this is to position your eye so that your line of sight is perpendicular to the scale and directly at the level of the meniscus. In a graduated cylinder, the liquid surface forms a curved shape (usually a concave meniscus), and the true volume corresponds to the bottom of that curve. So you should view the meniscus from eye level to ensure you’re looking straight at the bottom of the curve, giving an accurate reading. Viewing from above, below, or the side introduces perspective shifts and parallax errors.