JEE Main 20179 AprilOnline
- Exam
- JEE Main
- Year
- 2017
- Date
- 9 April
- Mode
- Online
- Subject
- Physics
- Chapter
- Gravitation
JEE Main 2017 · 9 April · Online · Physics · Gravitation
The mass density of a spherical body is given by ρ(r) = (k)/(r) for...
The mass density of a spherical body is given by for and for where is the distance from the center. The correct graph that describes qualitatively the acceleration, of a test particle as a function of is:








Options
- A

- B

- C

- D

Correct answer
A. 
Step-by-step solution
For Inside point
For outside point \left(r > R\right)E = gE = \dfrac{GM}{{r}^{2}}E = \dfrac{G}{{r}^{2}}\mathop{∫}_{0}^{R}( 4\pi{r}^{2}d{r}^{'} )( \dfrac{K}{{r}^{'}} )E = \dfrac{4\piKG}{{r}^{2}}{[ \dfrac{{{r}^{'}}^{2}}{2} ]}_{0}^{R}E = \dfrac{2\piKG}{{r}^{2}}{R}^{2}E ∝ \dfrac{1}{{r}^{2}}.