Question

Ram while drinking cold drink with a straw started playing with it and kept his thumb on the
top of the straw with cold drink in it. He was surprised to see that cold drink was not flowing
out of it. What is the reason behind this observation? Also give one application of the
scientific principle involved in the above situation,
Ans-​

Answer 1

Answer:

For capillary action the diameter of tube should be very small. Liquid rises in the capillary tube due to surface tension. But while drinking cold drinks, we need to create low pressure closer to mouth and due to the pressure difference between the top and the bottom of the straw, cold drink rises. So the rise of cold drink in straw is not due to capillary action.