Grades 8th - 12th by Animan Naskar
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Instructions : To induce charges, drag a charged rod to move it near the upper disc. To conduct charges into the electroscope, touch the rod to the upper disc.
What is Electric Charge?
Electric charge is the physical property of matter when it has more or fewer electrons than protons. In atoms, the electron carries a negative charge, and the proton carries a positive charge. The two types of charge are equal and opposite. Like charges repel and unlike charges attract. When electric charges flow in a conductor, it is called electric current.
What is Static Charge?
Static charge is excess of electric charge on an insulator. Static charge remains on the object until discharged when an object with opposite charge comes near or in contact. During storms, clouds build up lot of static charge that eventually discharges to the ground in form of lightning. In case of the electroscope, the rods and the leaves have static charge.
What is an Electromagnetic Field?
An electromagnetic field is generated by the movement of electric charge through a conductor. It affects the behavior of other charged objects in the vicinity of the field.
What is Electromagnetic Induction?
The electromagnetic field around a charged object induces opposite charge into other objects brought near it (no contact). These induced charges remain as long as the objects are in the electromagnetic field. In an electroscope, induction takes place when a charged rod is brought near it.
What is Electrical Conduction?
It is the movement of electrical charges through matter (usually conductor). Conduction only happens on contact. In an electroscope, conduction takes place when the charged rod is brought in contact with it.
What is an Electroscope?
An electroscope is an early scientific instrument that is still used to detect the presence, magnitude and type (+ve or -ve) of electric charge on a body. It is composed of a metal disc, metal rod and two metal leaves in a glass body. The metal leaves deflect in the presence of electrical charges.
How does an Electroscope Work?
There are two ways to charge an electroscope - by induction or conduction. When it is charged by induction, the metal disc acquires an opposite charge to the rod, and lower down, the metal leaves acquire the same charge as the rod. When it is charged by conduction, the charge from the rod flows into the electroscope. However in either case, the leaves acquire like charge and hence repel causing a deflection. The amount of deflection shows presence and magnitude of electric charge.