How does charge behavior affect a conducting rod's ends?

Click For Summary

Homework Help Overview

This discussion revolves around the behavior of charge on a conducting rod, particularly how it interacts with a negatively charged metal ball. The scenario involves a long conducting rod that is initially electrically neutral and examines the effects of bringing a charged object close to its ends.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the effects of a negatively charged ball on the ends of the conducting rod, questioning how charge distribution occurs after multiple contacts. They discuss the nature of attraction and repulsion between the charged ball and the rod's ends.

Discussion Status

The discussion is active, with participants offering various interpretations of the charge distribution on the rod after interactions with the charged ball. Some participants provide conflicting answers regarding the nature of the attraction or repulsion experienced by the rod's ends, indicating a lack of consensus on the correct responses.

Contextual Notes

Participants note that charges cannot remain at one end of the conductor, suggesting that charge distribution is a key aspect of the problem. There are indications of confusion regarding the specific questions and answers, which may affect the clarity of the discussion.

grandprix
Messages
28
Reaction score
0

Homework Statement



Here is a pretty straight forward question, i just wanted to double check my answers (in bold!)

This problem explores the behavior of charge on conductors. We take as an example a long conducting rod suspended by insulating strings. Assume that the rod is initially electrically neutral. For convenience we will refer to the left end of the rod as end A, and the right end of the rod as end B. In the answer options for this problem, "strongly attracted/repelled" means "attracted/repelled with a force of magnitude similar to that which would exist between two charged balls.

1) A small metal ball is given a negative charge, then brought near (i.e., within about 1/10 the length of the rod) to end A of the rod . What happens to end A of the rod when the ball approaches it closely this first time? It is strongly attracted

It is strongly repelled.
It is strongly attracted.
It is weakly attracted.
It is weakly repelled.
It is neither attracted nor repelled.

2) After a great many contacts with the charged ball, how is the charge on the rod arranged (when the charged ball is far away)? There is positive charge on end A with end B remaining neutral.

There is positive charge on end B and negative charge on end A.
There is negative charge spread evenly on both ends.
There is negative charge on end A with end B remaining neutral.
There is positive charge on end A with end B remaining neutral.

3)How does end A of the rod react when the charged ball approaches it after a great many previous contacts with end A? Assume that the phrase "a great many" means that the total charge on the rod dominates any charge movement induced by the near presence of the charged ball. I am not positive.. are they weakly attracted?

t is strongly repelled.
It is strongly attracted.
It is weakly attracted.
It is weakly repelled.
It is neither attracted nor repelled.

4)How does end B of the rod react when the charged ball approaches it after a great many previous contacts with end A?neither
It is strongly repelled.
It is strongly attracted.
It is weakly attracted.
It is weakly repelled.
It is neither attracted nor repelled.

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
2) In the conducting rod charges distribute through the conductor. In each contact some negative charge is transferred to the rod. So the choice is...

3) Now the rod is negatively charged. Some traces of negative charge may left out in the ball. Then the choice is...
 
2) It is weakly repelled (since side B is negative)
3) It is strongly repelled
 
grandprix said:
2) It is weakly repelled (since side B is negative)
3) It is strongly repelled
In 2) go through the choices.
In 3) The left out charge in the ball is very small. So the repulsion is..?
 
OOPS! I am sorry I read the wrong question..

2) there is negative charge on end A with end B remaining neutral.
3) weak repellsion
 
grandprix said:
OOPS! I am sorry I read the wrong question..

2) there is negative charge on end A with end B remaining neutral.
3) weak repellsion
2) is not correct. In the conductor charges cannot remain at one end.
 
rl.bhat said:
2) is not correct. In the conductor charges cannot remain at one end.

If they did, the electrons at the charged end would repel each other and distribute themselves evenly in a tiny fraction of a second.
 

Similar threads

Replies
6
Views
3K
  • · Replies 2 ·
Replies
2
Views
8K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 7 ·
Replies
7
Views
7K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 19 ·
Replies
19
Views
5K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 4 ·
Replies
4
Views
6K
Replies
1
Views
15K