Question

A child dipped two identical capillary tubes, one in a beaker containing mercury. He observed that water and mercury have risen through the tubes to a certain heights. 

1. Name this phenomenon. 

2. What difference did he observe in the shape of the meniscus of the two liquids in the tubes? 

3. If he plots a graph connecting the radius of the capillary tube and capillary height, what will be the shape of the graph?

Answer 1

1. Capillary rise. 

2. The shape of the water meniscus in the tube becomes concave upwards. But the shape of mercury measures in the tube become convex upward. 

3. h α, \(\frac{1}{r}\) this is in the form y α \(\frac{1}{x}\) 

Hence when we draw graph between ‘h’ and ‘r’ we get a graph of hyperbola.