Sensitivity of a Level Tube

The sensitivity of a level tube refers to its ability to accurately measure small changes in liquid level. It is an important factor in various applications, such as in surveying, construction, and engineering.

Factors Affecting Sensitivity

Several factors can affect the sensitivity of a level tube. Let's analyze each option to understand how it impacts the sensitivity:

a) Radius of Curvature
The sensitivity of a level tube is not directly affected by the radius of curvature of its inner surface. The curvature of the tube only affects its overall shape and size, but it does not have a significant impact on the sensitivity.

b) Diameter of the Tube
The diameter of the tube plays a crucial role in determining its sensitivity. A smaller diameter tube will have a higher sensitivity compared to a larger diameter tube. This is because a smaller diameter tube has a smaller cross-sectional area, resulting in a higher pressure difference for the same change in liquid level. Therefore, reducing the diameter of the tube increases its sensitivity.

c) Length of Vapour Bubble
The length of the vapor bubble in a level tube is not directly related to its sensitivity. The presence of a vapor bubble can affect the accuracy of the measurements, but it does not impact the sensitivity of the tube itself.

d) Viscosity and Surface Tension
Both viscosity and surface tension are properties of the liquid being measured and do not directly affect the sensitivity of the level tube. These properties impact the behavior of the liquid within the tube but do not alter the sensitivity of the tube itself.

Conclusion

Among the given options, the only factor that directly affects the sensitivity of a level tube is the diameter of the tube. Reducing the diameter increases the sensitivity, as it results in a higher pressure difference for the same change in liquid level. Therefore, option 'b' is the correct answer.

It is important to note that other factors, such as the quality of the tube, the accuracy of the scale, and the calibration of the instrument, can also influence the sensitivity of a level tube.