Question

Oingle Choice
4 x 1010 electrons are removed from a neutral
metal sphere of diameter 20 cm placed in air. The
magnitude of the electric field in (N C-1) at a
distance of 20 cm from its centre is​

Answer 1

ANSWER :

-1

Explanation:

Charge of each electron e=1.6×10

−19

C

Number of electrons removed from the sphere n=4×10

10

Thus total charged removed from the sphere q=ne

∴ q=4×10

10

×1.6×10

−19

=6.4×10

−9

C

Distance of point from the center of sphere r=20cm=0.2m

Thus electric field at that point E=

r

2

kq

where k=

4πϵ

o

1

=9×10

9

⟹ E=

(0.2)

2

9×10

9

×6.4×10

−9

=1440NC

−1