28. NCERT Exemplar XI

1. You might have observed on a dry day that when you touch the screen of a television or computer monitor (with a picture tube), you get a slight shock. Why does it happen?

 

It happens because the television screen or computer monitor are chargedare not charged and have static chargesnot having static charges accumulated on them and when we touch them with our hands which are chargeduncharged, the charges transfer through our hands and we get a slight shock.

 

2. If the materials used for constructing a building were good conductors, do you think lightning will strike the building. Will the lightning conductor be still required to be installed in the building?

 

Lightning will strikewill not strike the building because separation of charges can take placecannot take place in conductors and so, all the lightning falling on the building will reside onwill get inside the surface of the building.

All the work of lightning conductor is not doneis done by the conducting material itself , so there is no need of installinga need of installing lightning conductor.