# A small conducting sphere initially has a charge +q. The sphere is lowered into a conducting can.Which of the following quantities are fixed as the sphere is lowered but before it touches the can?a:Potential of the canb:Potential of the spherec:Charge on the sphered:Net charge on sphere and canI'm sure of c and d being correct considering the sphere is not touching the can, and applying charge conservation. I've also assumed the can is a closed one. (Please tell me if this is wrong). Further, option a cannot be right. And according to me 'b' seems plausible because it is moving in a region which had no prior electric field. So I've marked b,c and d. Although I'm very confused. what is the answer according to you guys?Thanks in advance

abc xyz
4 Points
13 years ago
Even the sphere and can does not change. This is because potetial of the sphere is kq/r. But due the induced charges nett potenial remains zero. this is because same amount of negative and positive charges reside on the can with approximately the same seperation. so nett potential remains constant. Hope this helps.
Nikola Tesla
11 Points
13 years ago

Untrue. The potential of the can has to change. You can intuitively think of it like this. Now there is a net positive charge on the outer surface of the can. So to bring a positive charge near it from infinity we are going to have to do some work. Hence it does have a potential now and initially it did not. Feel free to disagree with me if I'm wrong. Thanks for the reply.