Explaining Questions - STATIC ELECTRICITY

STATIC ELECTRICITY

1. Briefly explain each of the following observations;
   1. A plastic comb rubbed with hair attracts small pieces of papers
      
      When plastic comb rubbed with hair becomes negatively charged by gaining electrons from hair.
   2. TV screen covered by dusts after being used after period of time
      
      TV screen becomes electrically charged by induction hence attracts surrounding dusts.
2. Briefly explain what happen;
   1. When suspended ebonite rod rubbed with fur placed near by suspended Perspex rod rubbed with woolen cloth.
      
      Ebonite rod rubbed with fur acquires negative charges and Perspex rod rubbed with woolen cloth acquires positive charges hence they slightly attract each other.
   2. Both polythene rod rubbed with fur and plastic rod rubbed with hair suspended near to each other.
      
      Polythene rod rubbed with fur acquires negative charges and plastic rod rubbed with hair also acquires negative charges hence they slightly repel each other.
   3. Plastic pen rubbed with wet hair
      
      No movement of electrons from hair to plastic pen hence neither plastic pen nor hair will acquire charges.
3. With the aid of diagram briefly explain what happen when plastic tube rubbed with cotton cloth placed near to the nail
   
   Plastic tube when rubbed with cotton cloth becomes negatively charged. When placed near a nail it induces positive charges on the near side of the nail and negative charges on the opposite side hence they slightly attract each other.
4. Explain the following in terms of electrostatic concepts
   1. Small pieces of paper are first attracted towards a glass rod rubbed with silk but they immediately move away
      
      When a glass rod is rubbed with silk it becomes positively charged while the small pieces of paper are neutral.
      
      Due to induced opposite charges, the pieces of paper are attracted towards the glass rod.
      
      After touching the rod, the papers acquire similar charges to the rod and therefore repel away from it.
   2. Why a polythene rod becomes charged when rubbed with a duster. Why do you find it more difficult to charge it on a damp day than on a dry day?
      
      When a polythene rod is rubbed with a duster, electrons are transferred causing the polythene rod to become negatively charged.
      
      On a damp day, moisture in the air provides a conducting path for charges to leak away, making charging difficult compared to a dry day.
5. Explain why nylon clothes crackle as you undress.
   
   Friction between nylon clothes and the body causes transfer of electrons leading to buildup of static charges.
   
   When the clothes are removed, the charges discharge suddenly producing tiny sparks and crackling sounds.