Describe how you could use a pith ball as an electroscope

[sarah123]

Homework Statement

Describe how you could use a pith ball as an electroscope to identify the nature and presence of charge

Relevant Equations

Electrostatics Theory

Would it still work in a similar manner as an actual electroscope where you would charge it either positively or negatively and then observe attractive or repulsive forces or is there an easier and more efficient method?

 

[Steve4Physics]

Homework Statement: Describe how you could use a pith ball as an electroscope to identify the nature and presence of charge
Relevant Equations: Electrostatics Theory

Would it still work in a similar manner as an actual electroscope where you would charge it either positively or negatively and then observe attractive or repulsive forces or is there an easier and more efficient method?

Hi @sarah123 and welcome to PF. No one has replied yet so here are a few thoughts.

You haven't actually given your answer to the h/w question, so it's hard to reply to your query. But yes, the underlying approach is to charge the pith ball (PB) positively or negatively.

You need to
- describe the apparatus (even though it's simple);
- state how you would you give the PB a positive charge and how would you give it a negative charge;
- give a brief explanation of how you would then use the apparatus.

For a good answer, you might want to consider the following issues:

Could a charged PB attract a neutral object (one with no net charge)? If so, how could you check if an object is neutral?

Is it possible to get a misleading result? E.g. a positively charged object attracting a positively charge PB?

[Minor edits made]

 

[haruspex]

What will the pith ball be attracted or repulsed by?
I note it mentions the "nature" of the charge. If that means positive or negative then I don't think that a standard gold leaf electroscope can do that.

 

[Steve4Physics]

I note it mentions the "nature" of the charge. If that means positive or negative then I don't think that a standard gold leaf electroscope can do that.

If the gold leaf electroscope is given a prior net charge (of known sign) the leaves will diverge and remain so.

Then a charged object is brought near to the cap.

There will be either an increase or a decrease in the divergence of the leaves, depending on the sign of the object's charge.

I've never actually done it, but it should work.