Some Natural Phenomena class 8 | CBSE Worksheet for class 8
Some Natural Phenomena class 8. Download some natural phenomena, class, 8 worksheet pdf based on latest CBSE syllabus including fill up, long question, answer in one word and more.
Some Natural Phenomena ncert grade 8 chapter 15
When two bodies are charged by rubbing against each other, they acquire equal and opposite charges.
Repulsion alone us a sure test of whether a body is charged or not
The comb or balloon are said to be electrically charged when they are rubbed against the hair. They acquire an electrical charge.
Like charges repel each other and unlike charges attract each other.
Charges can flow through the copper wire, but cannot flow through the plastic.
Benjamin Franklin that clouds build up charge during a storm
An electroscope is an instrument used to detect and test the natural charges
A seismograph is an instrument for measuring the magnitude of an earthquake
Ion is an electrically charged atom or molecule.
When a plastic refill is rubbed with polythene, it acquires a small electric charge. Similarly, when a plastic comb is rubbed with dry hair, it acquires a small charge. These objects are called charged objects. In the process of charging the refill and the plastic comb, polythene and hair also get charged.
It is a convention to call the charge acquired by a glass rod when it is rubbed with silk as positive. The other kind of charge is said to be negative. It is observed that when a charged glass rod is brought near a charged plastic straw rubbed with polythene there is an attraction between the two.
The process of transferring of charge from a charged object to the earth is called earthing. Earthing is provided in buildings to protect us from electrical shocks due to any leakage of electrical current.
A lightning Conductor is a device used to protect buildings from the effect of lightning. A metallic rod, taller than the building, is installed in the walls of the building during its construction. One end of the rod is kept out in the air and the other is buried deep in the ground The rod provides an easy route for the transfer of electric charge to the ground.
What is an Earthquake?
An earthquake is a sudden shaking or trembling of the earth which lasts for a very short time. It is caused by a disturbance deep inside the earth’s crust. Earthquakes occur all the time, all over the earth. They are not even noticed. Major earthquakes are much less frequent. They can cause immense damage to buildings, bridges, dams and people. There can be a great loss to life and property.