Question

The electric field everywhere on the surface of a thin, spherical shell of radius 0.800 m is of magnitude 902 N/C and points radially toward the center of the sphere.
(a) What is the net charge within the sphere's surface?

Answer 1

Explanation:

(a) From E=

r

2

k

e

​

Q

​

Q=

k

e

​

Er

2

​

=

(8.99×10

9

N⋅m

2

/C

2

)

(8.90×10

2

N/C)(0.750m)

2

​

=5.57×10

−8

C

But Q is negative since  

E

→

 points inward, so

Q=−5.57×10

−8

C=−55.7nC

(b) The negatve charge has a spherically symmetric charge distribution, concentric with the spherical shell