Write answers the following questions.
(a) Why does friction cause a charge to develop?
(b) Why is the charge developed due to friction called a static electric charge?
(c) Why does the charge developed by induction disappear quickly?
(d) Why do the leaves of a gold leaf electroscope fly apart when a charged body touches its disc?
(e) What causes the cracking sound we hear as we wear a cardigan?
Write answers the following questions.
(a) Why does friction cause a charge to develop?
(b) Why is the charge developed due to friction called a static electric charge?
(c) Why does the charge developed by induction disappear quickly?
(d) Why do the leaves of a gold leaf electroscope fly apart when a charged body touches its disc?
(e) What causes the cracking sound we hear as we wear a cardigan?
(a) When we rub two substances they get charged due to friction. Friction between two substances produces heat in the substance and due to this their loosely-bound electrons get energy to move from one into another substance. The substance which loses electrons becomes positively charged and other one becomes negatively charged.
(b) The charge developed due to friction is called a static electric charge because this charge does not move.
(c) In the electrical induction phenomena if the charged body is removed from the induced charged body, the induced charges on the opposite ends of the body mix together again and no charge will remain on it. Due to this reason, the charge developed by induction disappears quickly.
(d) When a charged body touches the disc of an electroscope, the charge is transfered to it and it moves to the leaves of the electroscope. As both the leaves get similar charges there is repulsion between them and they fly apart. Therefore, the leaves of a gold leaf electroscope fly apart when a charged body touches its disc.
(e) A cardigan is made of wool. Friction between the parts of the cardigan allows the transfer of electrons from one position to another. Due to this some charge is accumulated at certain points. Whilst wearing the cardigan this accumulated charge discharges and a transfer of electrons takes place. The passage of electrons through the air in the form of sparks let out heat and sound energy. Therefore, we hear the crackling sound and in dark rooms we may see the spark lights as well.
(a) When we rub two substances they get charged due to friction. Friction between two substances produces heat in the substance and due to this their loosely-bound electrons get energy to move from one into another substance. The substance which loses electrons becomes positively charged and other one becomes negatively charged.
(b) The charge developed due to friction is called a static electric charge because this charge does not move.
(c) In the electrical induction phenomena if the charged body is removed from the induced charged body, the induced charges on the opposite ends of the body mix together again and no charge will remain on it. Due to this reason, the charge developed by induction disappears quickly.
(d) When a charged body touches the disc of an electroscope, the charge is transfered to it and it moves to the leaves of the electroscope. As both the leaves get similar charges there is repulsion between them and they fly apart. Therefore, the leaves of a gold leaf electroscope fly apart when a charged body touches its disc.
(e) A cardigan is made of wool. Friction between the parts of the cardigan allows the transfer of electrons from one position to another. Due to this some charge is accumulated at certain points. Whilst wearing the cardigan this accumulated charge discharges and a transfer of electrons takes place. The passage of electrons through the air in the form of sparks let out heat and sound energy. Therefore, we hear the crackling sound and in dark rooms we may see the spark lights as well.
