- #1

songoku

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- Homework Statement
- A metallic sphere of radius 1.0 cm is charged with 1.0 x 10^9 electrons in air.

Which of the following is closest to the electric potential difference between

the surface of this sphere and a point far away?

a. 70 V

b. 140 V

c. - 70 V

d. - 140 V

e. 9 x 10^20 V

- Relevant Equations
- V = kQ/r

V at surface = k Q / r = 9 x 10

= - 144 V

V at a point far away = 0 V

From the sentence "electric potential difference between the surface of this sphere and a point far away" means that the question asks about V at surface minus V at far away so the answer is -144 V?

Thanks

^{9}x (1 x 10^{9}x (-1.6 x 10^{-19}) / (1 x 10^{-2})= - 144 V

V at a point far away = 0 V

From the sentence "electric potential difference between the surface of this sphere and a point far away" means that the question asks about V at surface minus V at far away so the answer is -144 V?

Thanks