Will the voltage or potential difference change?

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Homework Help Overview

The discussion revolves around concepts of electrostatics, specifically focusing on the behavior of charged objects and the effects on an electroscope. Participants explore the implications of charge redistribution and the relationship between distance and electric field intensity.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the behavior of charges in an electroscope when a positively charged rod is brought near it, questioning the resulting charge on the knob and the leaves. They also explore the relationship between distance and electric field intensity, raising questions about how moving one charged sphere affects the distance to a point nearby.

Discussion Status

There is an active exploration of the concepts, with participants questioning assumptions about charge neutrality and the behavior of electrons in response to nearby charges. Some guidance has been offered regarding charge redistribution, but multiple interpretations and questions remain open.

Contextual Notes

Participants express uncertainty about the effects of distance changes on electric field intensity and potential difference, indicating a need for clarification on these concepts. The discussion also reflects a lack of familiarity with the electroscope's operation and the implications of charge movement.

MIA6
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1. A positive charged rod is held near, but does not touch a neutral electroscope. The charge on the knob becomes
1) positive and the leaves become positive 2) positive and the leaves become negative.
3) - and the leaves become + 4) - and the leaves become -.
I chose 1), but it's wrong. I am not really familiar with electroscope and how they work.

2. There are two positive charged spheres, A and B (A is at the left, B is at the right), 3 meters apart. There is a point x left to the A. If sphere A is moved toward sphere B, the electirc field intensity at point x will
1) decrease 2) increase 3) remain the same
I chose 2) since E=V/d, so when d decreases, E increases. But the answer is 1), so I am wondering if the voltage changes as well? so in general, If there is a change in distance between two charges, will the voltage or potential difference change? if not, then what will affect the potential difference?

Thanks.
 
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MIA6 said:
1. A positive charged rod is held near, but does not touch a neutral electroscope. The charge on the knob becomes
1) positive and the leaves become positive 2) positive and the leaves become negative.
3) - and the leaves become + 4) - and the leaves become -.
I chose 1), but it's wrong. I am not really familiar with electroscope and how they work.
What happens to the electrons in the knob when the positive charge is brought close to them?
 


The point x is to the left of sphere A...so how does d between sphere A and point x change as sphere A moves towards sphere B?
 


Hootenanny said:
What happens to the electrons in the knob when the positive charge is brought close to them?

Then there is a redistribution of charge within the object? like the electrons will get to the side where the positive charge is brought to. But then will it stay neutral, and how about the leaves?
 


fizikx said:
The point x is to the left of sphere A...so how does d between sphere A and point x change as sphere A moves towards sphere B?

d between sphere A and point x will also change when A moves toward B because then A is going far away from point x.
 


MIA6 said:
Then there is a redistribution of charge within the object? like the electrons will get to the side where the positive charge is brought to.
Correct :approve:
MIA6 said:
But then will it stay neutral, and how about the leaves?
Overall, the object is still neutral since there is still the same amount of positive and negative charge on the object. However, if some of the electrons move towards the knob as you correctly say, this means that on the knob there will be more [negative] electrons than [positive] lattice ions; hence the knob will have a net negative charge.

Do you follow?
 


Hootenanny said:
Correct :approve:

Overall, the object is still neutral since there is still the same amount of positive and negative charge on the object. However, if some of the electrons move towards the knob as you correctly say, this means that on the knob there will be more [negative] electrons than [positive] lattice ions; hence the knob will have a net negative charge.

Do you follow?

yes, then what about the leaves?
 


MIA6 said:
yes, then what about the leaves?
These electrons the move towards the knob, where do you suppose they come from?
 

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