A child staying in a caostal region tests the drinking water and also the seawater with his tester.He finds that the compass needle deflects more in the case of sea water. Can you explain the reason ?

When the free ends of the tester are dipped into a solution, the magnetic needle shows deflection. Can you explain the reason ?

Paheli had heard that rainwater is 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 reason ?