Question

Mass density of a solid sphere is ρ. Radius of the sphere is R. The gravitational field at distance r from the centre of the sphere inside it is

• A. $\frac{4\rho G\pi r}{3}$
• B. $\frac{4\rho G{r}^2}{3}$
• C. $\frac{4\rho G{R}^3}{3r^2}$
• D. $\frac{\rho G{R}^3}{\pi r}$

Answer 1

The correct option is A

$\frac{4\rho G\pi r}{3}$

$E\left(r\right)=\frac{GM}{R^3}rforr\le R=\frac{G}{R^3}(\frac{4}{3}\pi R^3.\rho r)=\frac{4Gr\pi \rho }{3}$