Question

A spherical conductor of radius 10 cm has a charge of 3.2 x 10^-7 C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere?

`(1/(4 pi epsilon_0) = 9 xx 10^9 "Nm"^2 // "C"^2)`

विकल्प

• 1.28 x 10⁵ N/C

• 1.28 x 10⁶ N/C

• 1.28 x 10⁷ N/C

• 1.28 x 10⁴ N/C

Answer 1

1.28 x 10⁵ N/C

Explanation:

lf R is radius of sphere and r is distance of point from centre of sphere then, for r > R

`"E" = "q"/(4 pi epsilon_0 "r"^2)`

`= 1/(4 pi epsilon_0) xx (3.2 xx 10^-7)/(15 xx 10^-2)^2`

`= 9 xx 10^9 xx (3.2 xx 10^-7)/(225 xx 10^-4)`

`= 1.28 xx 10^5  "N/C"`