# What is the capacitance of the two metal spheres

## Homework Statement

What is the capacitance of the two metal spheres shown in the figure ?

sphere one has 20nC of charge and the other has -20nC of charge. The change in voltage is 100V

## Homework Equations

C=Q/(change in V)

## The Attempt at a Solution

My question is how do yo determine what charge to put in for Q?

## Homework Statement

What is the capacitance of the two metal spheres shown in the figure ?

sphere one has 20nC of charge and the other has -20nC of charge. The change in voltage is 100V

## Homework Equations

C=Q/(change in V)

## The Attempt at a Solution

My question is how do yo determine what charge to put in for Q?

It's given.

It's given.

but the thing is how would I know to use 20nC or -20nC? What if you had 2 charges that were something like -30nC and 20nC? How do you know what Q to choose?

but the thing is how would I know to use 20nC or -20nC? What if you had 2 charges that were something like -30nC and 20nC? How do you know what Q to choose?

you will never be given a problem like that. the charge when dealing with capacitance will be symmetric if two values are given or it will be singular(where such an ambiguity is impossible)

So i assume then that the answer here is just 2E-8/100 then

So i assume then that the answer here is just 2E-8/100 then

assumed correct.

assumed correct.

Correct

thanks