Question

Dependence of intensity of gravitational field $(E)$ of earth with distance $(r)$ from centre of earth is correctly represented by

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

For a point inside the earth i.e. $r< R$
$E=-\frac{G M}{R^{3}} r$
where $M$ and $R$ be mass and radius of the earth respectively.
At the centre, $r=0$
$\therefore E=0$
For a point outside the earth i.e. $r>R$,
$E=-\frac{G M}{r^{2}}$
On the surface of the earth i.e. $r=R$,
$E=-\frac{G M}{R^{2}}$
The variation of $E$ with distance $r$ from the centre is as shown in the figure.