Paheli had heard that rainwater is as good as distilled water. So she collected some rainwater in a clean glass tumbler and tested it using a tester. To her surprise she found that the compass needle showed deflection. What could be the reasons?  

 

Answer

Rainwater is said to be pure water.

But when rainwater falls to the earth, it dissolves various acidic gases in it like carbon dioxide, sulphur dioxide etc and becomes acidic.

We know that acids are good conductors of electricity, so rainwater becomes a good conductor of electricity.

Hence, the compass needle shows deflection

Ask a doubt
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo