WATER BULGE | Urdu
Channel: Arvind Gupta
Date: 2016-06-18

This is a very dramatic experiment through which we can learn something about surface tension. Fill a glass with colored water and also need lots of coins. Fill the glass with more colored water until it is level full. Add some more water with the help of a dropper. Keep adding until you can add no more water and it is full to the brim. Now take a coin and gently drop it vertically into the glass. Keep adding coins one after the other. You will be surprised at how many coins can a seemingly full glass of water swallow. This is because the water has a skin on its surface. Though this skin swells because of surface tension it is kept inside the glass. Add some more coins. You will see the water surface bulge out and become convex. Even at this stage you can still add some more coins. In the end the water will spill out but before that the glass would have swallowed many-many coins. This is all because of surface tension. Now pour out all the water from the glass and see how many coins it has swallowed. Isn’t this fun!

This work is supported by IUCAA (www.iucaa.in) and TATA Trust (www.tata.com/aboutus/sub_index/Tata-trusts)

Credits:,Ashok Rupner, Manish Jain, Pradnya Pujari, Shivaji Mane, Jyoti Hiremath, Arvind Gupta, Vidula Mhaiskar

Dubbed in Urdu by Ishrat Shaik from Pratham's Science Learning Program TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org