Question

the electric field is 100V/m, at a distance of 20cm from the centre of a dielectric sphere of radius 10cm. Then E at 3cm distance from the centre of sphere is​

Answer 1

Answer:

Correct option is

C

120V/m

REF.Image.

Electric field from distance = 100 N/m

R = Radius = 100m

when (r>R)

So E=

r

2

Kθ

100=

20×20×10

−4

Kθ

Kθ=400×10

−2

...(i)

and Electric field from centre distance is 3 cm.

(when r<R) E=

R

3

Kθr

from (i)equation

=

10×10×10×10

−6

400×10

−2

×3×10

−2

=

10

−3

4×3×10

−2

=120V/m

E=120V/m