Important One Liners on Electric Charges ------------------ | NEET EXAM PDF
Important One Liners on Electric Charges
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If an object is attracted by another charged body, the first object may be oppositely charged or not charged because we know both an uncharged object and an oppositely charged object are attracted by another charged object.
If an object is positively charged it loses some of its electrons. The mass of an electron is 9.11*10^-31 kg. So, if a positively charged body loses ‘n’ number of electrons, it mass decrease by the amount n*9.11E^-31kg.
Though gold is a costly metal it is used in electroscope because of the property malleability. This means very thin and light sheets can be formed from gold simply by hammering or rolling and hence the deflection of the light gold plates increases.
The divergence of the plates of the Gold-leaf oscilloscope depends only on the presence of a charge, not on the quality of charge i.e. positive or negative. So, if the charge changes from positive to negative and vice versa the degree of divergence of the plates remains the same.
The same charges repel each other. So, they try to maintain maximum distance from each other and hence they try to remain at the outer surface of an object. If the charge remains on the inner surface or throughout the body, they will repel each other with greater force.
The human body is a good conductor and hence the charge produced by friction flew through his body to the ground. We can tackle the problem simply by holding the brass rod with the help of some insulated holder.
If the apparatus is initially in contact with some positively charged body and then comes in contact with another charged body and if the divergence increases we can deduce that the second body is also positively charged. If the divergence decreases then the second body must be negatively charged.
According to electrostatic series, glass is situated above silk. So, if the glass is rubbed with silk, the positive charge on glass and negative charge on silk is produced. Similarly, we can predict what is the nature of charge if we rub two di-electric substances together.
1 Coulomb means 3*10^9 Electro Static Unit of charge. Coulomb and ESU are two different units of charge and their conversion formula is necessary. Coulomb is the unit of charge in the SI system and esu is the unit of charge in the CGS system.
The two spheres are oppositely charged by the same amount. So if they come in contact, both of their charges are neutralized. So they become uncharged and don’t attract or repel each other.
