Can an Insulator Acquire Same Charge as Charged Body?

In summary, when a charged body is brought near an insulator, the side facing it acquires a charge of opposite sign due to induction. It is possible for an insulator to acquire the same charge as the charged body through field-emission of electrons in high electric fields or by collecting electrons from other field-emitting sources. However, charge cannot be induced on insulators through Faraday induction. In high voltage situations, charge can be deposited in insulators. In the case of a van deGraaff generator, the combs "wipe" charge onto the conducting, dielectric belt, which is then transferred to the metal sphere at the top where it can build up before draining away.
  • #1
akhil123
14
0
When a charged body is brought near an insulator, the side facing it acquires a charge of opposite sign because of induction. Is it possible for an insulator to acquire same charge as charged body? (by induction, touching or any other means)
 
Physics news on Phys.org
  • #2
akhil123 said:
When a charged body is brought near an insulator, the side facing it acquires a charge of opposite sign because of induction. Is it possible for an insulator to acquire same charge as charged body? (by induction, touching or any other means)

Yes. The belt on a van deGraaff generator picks up charge in this way.
 
  • #3
An insulator in an electric field gets charged positively by field-emission of electrons in very high electric fields, or negatively by electrons collected from other field-emitting sources. Charge cannot be induced (Faraday induction) on insulators. In very high voltage situations, charge can get deposited in (as opposed to on) insulators.

Bob S
 
  • #4
Bob S said:
An insulator in an electric field gets charged positively by field-emission of electrons in very high electric fields, or negatively by electrons collected from other field-emitting sources. Charge cannot be induced (Faraday induction) on insulators. In very high voltage situations, charge can get deposited in (as opposed to on) insulators.

Bob S

I was referring to the "other means" part of the question. In the Wikipedia description of a van deGraaff generator, it looks to me like the combs "wipe" charge onto (or into) the conducting, dielectric belt. Once conveyed to the large metal sphere at the top of the loop, the charges are wiped off of (or out of) the belt by the upper comb, and migrate to the sphere's outer surface where they can build up considerably before spontaneously draining away into the ambient air.
 
  • #5
Thanks a lot
 
  • #6
akhil123 said:
Thanks a lot

You're welcome. I know the "scraping" idea is a lame one, but it was how one of these contraptions was explained to me in a high school physics class.
 

1. How does an insulator acquire charge?

An insulator can acquire charge through a process called triboelectricity, where it gains electrons from another material through friction.

2. Can an insulator acquire the same charge as a charged body?

Yes, an insulator can acquire the same charge as a charged body through contact or induction, depending on the type of insulator and the properties of the charged body.

3. Is it possible for an insulator to acquire a charge without touching a charged body?

Yes, an insulator can acquire charge through induction, where it is brought near a charged body and the electrons within the insulator are redistributed, creating a temporary charge imbalance.

4. How long can an insulator hold on to its acquired charge?

The length of time an insulator can hold on to its acquired charge depends on various factors such as the material of the insulator, the humidity level, and the type of charge acquired. In general, insulators can hold on to their charge for a longer period compared to conductors.

5. Can an insulator lose its acquired charge?

Yes, an insulator can lose its acquired charge through various means such as touching a conductor, exposure to high temperatures, or being exposed to a strong electric field. However, insulators have a higher resistance to losing charge compared to conductors.

Similar threads

Replies
4
Views
627
Replies
10
Views
2K
  • Electromagnetism
2
Replies
39
Views
6K
Replies
4
Views
717
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
1K
Replies
11
Views
724
  • Electrical Engineering
Replies
3
Views
4K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
26
Views
549
Back
Top