Assuming the earth to be a sphere of uniform mass density, the weight of a body at a depth \( d = \dfrac{R}{2} \) from the surface of earth, if its weight on the surface of earth is \( 200 \, \text{N} \), will be: (Given \( R \) = radius of earth)
\( 400 \, \text{N} \)
\( 100 \, \text{N} \)
\( 500 \, \text{N} \)
\( 300 \, \text{N} \)
