Electrostatics Lab

8.1.1 Electroscopes
1. Yes. As we rub the rod harder, it will gain more electron and be negatively charged, causing the vanes separate further due to the amount of the electrons.
2. When the negatively charged rod is pulled back without touching the electroscope (induction), the positively charged electroscope will move to the vanes, which is negatively charged now. This will bring the vanes closer together.
3. They produce the same effect because when the positively charged rod is brought closer to the electroscope, the electroscope now will be negatively charged, leaving the vanes positively charged, thus the vanes repel.
4. Because the electroscope has obtained negative charges from the rod through conduction process. The electroscope is still negatively charged when the rod had been removed.

8.1.4 Induction

1. The glass will be positively charged after it had been rubbed with silk. The positive charged in the paper are repelled downwards. The upper side of the paper becomes negatively charged and is therefore attracted toward the positive glass.
2. Because when the paper acquires charges from the glass by conduction, it will be repelled due to similar charges with the glass.
3. The bob will first be attracted by the charged plastic rod by induction, then it acquired a similar charged by conduction, then will be repelled due to similar charges. Now the bob is negatively charged. When the charged bob contact with the uncharged glass rod, the glass rob acquires charges from the bob as thus be same charged. The bob therefore will be repelled by two rods, causing it to bounce back and forth between the two rods.
4. The Cheerios will be charged by conduction when the Vande Graaf generator is turned on. Then the Cheerios fly up because of the repulsion of like charges.
5. This could be explained that the hair on my arm will be attracted by the negatively charged electrons in the cloud, which is much more when the lightning is about to strike.

8.1.5 Distribution of Charge

1. The tiny blue beam at the end of the metal rod indicates the transfer of the electrons from the dome to the rod.
2. The lightning rod is an excellent conductor that allows the current to flow to ground without causing any damage.

8.1.6 Electrostatic Separators

1. Adding water to the mixture of salt and pepper, mixing it until salt is dissolved. Once salt has dissolved in water use filter paper and funnel to filter the pepper out of the salt and water. (Chemistry)
3. Those areas not covered by paper are charged and therefore attract pepper.

8.1.7 Electric Potential

1. An electric field strikes the fluorescent material that lines the lamp interior and causes it to glow.
2. Because the electric field is operated perpendicular to the surface of the object. Thus the tube does not glow brightly when positioned tangential to the surface of the dome.