Question

Question 12
The weight of an object at the center of the earth of radius R is

(a) zero
(b) infinite
(c) R times the weight at the surface of the earth
(d) $\frac{1}{R^2}$ times the weight at surface of the earth

Answer 1

(a) zero

Let $m$ be the mass of the object, $W$ be the weight of the object and $g$ be the acceleration due to gravity.
We know, $W=mg$
Since $g=0$ at the center of the earth,
$W=m\times 0=0$
Therefore, the weight of an object at the center of the earth of radius R is zero.