Kavya observed that a discharged dry cell which kept in sun light by her father for few hours got ability to glow LED. She got many doubts and questions to raise. Can you guess those questions or doubts?

Collect the information and make list of good conductors and bad conductors. How do you use this information in your daily life works?

In many of the activities in this chapter, we have used a tester made up of LED. Can we avoid LED and use something else as a tester? Magnetic compass needle could be an alternative tester. We know that when we take a current carrying wire near magnetic compass needle, it shows deflection. Use this property to make a tester of magnetic compass needle. You may refer to the following figure.

Kavya observed that a discharged dry cell which kept in sun light by her father for few hours got ability to glow LED. She got many doubts and questions to raise. Can you guess those questions or doubts?

Make a battery from four lemons and test it with a LED in the circuit.

In case of a fire, before the fire men use the water, they shut off the main electrical supply for the area. Explain why they do this?

Which energy is cause for glowing of bulb in electrolytic cell?