In order to test the presence of a charge on an object, the object is brought near to an uncharged pith ball. If the object is charged, the ball will be attracted to it and move toward it.
The attraction occurs because of induced polarisation of the atoms inside the pith ball. The pith is a nonconductor, so the electrons in the ball are bound to atoms of the pith and are not free to leave the atoms and move about in the ball, but they can move a little within the atoms.
If, for example, a positively charged object is brought near the pith ball, the negative electrons in each atom will be attracted and move slightly toward the side of the atom nearer the object. The positively charged nuclei will be repelled and will move slightly away.
Since the negative charges in the pith ball are now nearer the object than the positive charges, their attraction is greater than the repulsion of the positive charges, resulting in a net attractive force.
This separation of charge is microscopic, but since there are so many atoms, the tiny forces add up to a large enough force to move a light pith ball.
source:
http://en.wikipedia.org/wiki/Electroscope
If you touch the knob of a positively charged electroscope with a negatively charged object, the excess electrons from the negatively charged object will flow to the electroscope, neutralizing the positive charge. The electroscope will become neutral or slightly negatively charged as a result.
If you touch a positively charged object to a positively charged electroscope, the electroscope may become even more positively charged due to the transfer of additional positive charge. This could result in greater divergence of the leaves of the electroscope, indicating a higher level of positive charge on the electroscope as a result of the contact with the positively charged object.
The golden leaf electroscope can be charged positively by induction by first bringing a positively charged object close to the electroscope. The positive charges on the object attract the negative charges in the electroscope, causing the positive charges in the electroscope to be repelled to the leaves, thus giving the electroscope a positive charge.
When the knob of the electroscope touches a positively charged object, electrons from the object are transferred to the electroscope, causing it to become positively charged. This causes the gold leaves to repel each other due to the like charges, spreading apart and indicating the presence of a positive charge on the electroscope. A diagram would show the initial position of the gold leaves close together, then spreading apart when the electroscope becomes positively charged.
A positively charged object will cause the leaves of the electroscope to separate or diverge. A negatively charged object will cause the leaves to come together or converge.
If you touch the knob of a positively charged electroscope with a negatively charged object, the excess electrons from the negatively charged object will flow to the electroscope, neutralizing the positive charge. The electroscope will become neutral or slightly negatively charged as a result.
If you touch a positively charged object to a positively charged electroscope, the electroscope may become even more positively charged due to the transfer of additional positive charge. This could result in greater divergence of the leaves of the electroscope, indicating a higher level of positive charge on the electroscope as a result of the contact with the positively charged object.
The golden leaf electroscope can be charged positively by induction by first bringing a positively charged object close to the electroscope. The positive charges on the object attract the negative charges in the electroscope, causing the positive charges in the electroscope to be repelled to the leaves, thus giving the electroscope a positive charge.
When the knob of the electroscope touches a positively charged object, electrons from the object are transferred to the electroscope, causing it to become positively charged. This causes the gold leaves to repel each other due to the like charges, spreading apart and indicating the presence of a positive charge on the electroscope. A diagram would show the initial position of the gold leaves close together, then spreading apart when the electroscope becomes positively charged.
Attraction and repulsion, in physics means, is when two objects attract and repel one another. For example, an When a negatively charged rod is brought near an electroscope with negatively charged leaves, the leaves will repel. Same goes for when a positively charged rod is brought near an electroscope with positively charged leaves, the leaves will repel. But if a negatively charged rod is brought near an electroscope with positively charged leaves, the leaves will attract. Kind of like opposites attract, and likeness repels.
A positively charged object will cause the leaves of the electroscope to separate or diverge. A negatively charged object will cause the leaves to come together or converge.
Like charges repel. Unlike charges attract. Therefore, you would expect them to repel each other.
You can use an electroscope to see if something is charged. When a charged object is brought near the electroscope, the leaves of the electroscope will either repel or attract each other, indicating the presence of a charge.
When a positively charged body is brought close to a gold leaf electroscope, the electrons in the electroscope will be repelled towards the top of the leaves, causing them to diverge. This happens because like charges repel each other, and the positive charge on the body repels the electrons in the electroscope leaves.
To determine if a metal leaf electroscope is neutral, bring a charged rod near the metal cap. If the metal leaves diverge, the electroscope is neutral. If the metal leaves collapse or diverge more, the electroscope is positively charged.
If the leaves of an electroscope hang down, it typically indicates that the electroscope is positively charged since like charges repel each other. The excess positive charge on the electroscope causes the leaves to spread apart due to the repulsive force.
The leaves of the electroscope will repel each other and diverge further apart. This is because like charges (positive) repel each other, causing the leaves to move away from each other due to the force exerted by the positively charged rod.