During thunderstorm, if we carry an umbrella while crossing an open field, the electric discharge can pass through the metallic stick of the umbrella and can give an electric shock to the person holding it.

An electroscope works on the principle that like charge repel each other. So the connecting rod and the leaves of the electroscope are made out of metals which are good conductors of electric charges.

When the metal disc of an electroscope is touched with a charged glass rod, the electric charge gets transferred to the metal leaves through the rod. Since both the leaves have similar charges, they repel each other and get diverged.

i) When a glass rod is rubbed with a silk cloth the free electrons in the glass rod are transferred to silk cloth. It is because the free elections in the glass rod are less tightly bound as compared to silk cloth.
ii) Glass rod acquires a positive charge due to loss of electrons. Silk cloth acquires a negative charge as it gains electrons.
iii) Here, transfer of charges occur due to friction.

Uses of electroplating:
(i) Zinc is deposited over Iron by electroplating to protect it from corrosion and rust formation. It is used in automobile industries.
(ii) Wheel rims, car parts, bath taps etc. requires a non-corrosive, non-scratchy, shiny metal. Chromium suits well but it is expensive. So they are made from a cheaper metal and a coating of chromium is deposited over it by electroplating.

The path through which electrons flow from one terminal to another terminal of the source is called electric circuit.

When two materials are rubbed together, some electrons are transferred from one material to the other, leaving them both with a net electric charge.
E.g. When a glass rod is rubbed with a silk cloth the free electrons in the glass rod are transferred to silk cloth. Thus, the glass rod acquires a positive charge and the silk cloth acquires a negative charges.

Electroplating : 
The process of depositing a layer of one metal over the surface of another metal by passing electric current is called electroplating.

Procedure:
1. Take a glass jar and fill it with copper sulphate solution.
2. Take a copper metal plate and connect it to the positive terminal of the battery.
3. Connect an iron spoon to the negative terminal of the battery.
4. Now, dip them in the copper sulphate solution.
5. Pass electric current through the copper sulphate solution.
6. A thin layer of copper metal is deposited on the iron spoon and an equivalent amount of copper is lost by the copper plate.

Lightning:
i) Lightning is an example of discharge that takes place in clouds.
ii) Lightning is produced by discharges of electricity from cloud to cloud or from cloud to ground.
iii) During thunderstorm air is moving upward rapidly and it carries small ice crystals upward. At the same time, small water drops move downward.
iv) When they collide, ice crystals become positively charged and more upward and the water drops become negatively charged and move downward.
v) So the upper part of the cloud is positively charged and the lower part of the cloud is negatively charged.
vi) When they come into contact, electrons in the water drops are attracted by the positive charges in the ice crystals.
vii) Thus electricity is generated and lightning is seen.
viii) Sometimes, the lower part of the cloud which is negatively charged comes into contact with the positive charges accumulated near the mountains, trees and even people on the earth.
ix) This discharge produces a lot of heat and sparks that results in lightning.
x) Huge quantities of electricity are discharged in lightning flashes and temperatures of over 30,000°C or more can be reached.

Three ways of charge transfer:-
(i) Transfer by friction
(ii) Transfer by conduction
(iii) Transfer by Induction
(i) Transfer by friction:-
1. When two materials are rubbed together some electrons are transferred from one material to the other, leaving them both with a net electric charge.
2. E.g. when a glass rod is rubbed with a silk cloth, the free electrons in the glass rod are transferred to silk cloth.
3. Glass rod acquires a positive charge and the silk cloth acquires a negative charge.
(ii) Transfer by conductions :
1. Charges can be transferred to an object by bringing it in contact with a charged body. The method of transferring charges from one body to other body is called transfer by conduction.
2. E.g. when a negatively charged ebonite rod is brought near a hollow paper cylinder, negative charges in the rod are attracted by the positive charges in the cylinder.
3. When the paper cylinder is touched by the rod, some negative charges are transferred to the paper cylinder and they repel each other.
(iii) Transfer by Induction:
1. The process of charging an uncharged body by bringing a charged body near to it but without touching it is called induction.
2. E.g. when a negatively charged plastic rod is brought near a neutral rod, the near end of the neutral rod becomes positively charged and the farther end becomes negatively charged.