Gravitation

JEE Main level, single correct, medium

55 of 223

Question 55 of 223

The acceleration due to gravity on the surface of earth is gg. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be :

Show answer and solution

Answer: (D) 4g4g

The acceleration due to gravity is related to the mass and the radius of the Earth by the formula:
g=GMR2⇒g∝1R2...(1)g=\dfrac{GM}{{R}^{2}}\Rightarrow g\propto \dfrac{1}{{R}^{2}}...\left(1\right)
Thus, from equation (1), it follows that
g2g1=R12R22=R12(R12)2=4⇒g2=4g\dfrac{{g}_{2}}{{g}_{1}}=\dfrac{{R}_{1}^{2}}{{R}_{2}^{2}} =\dfrac{{R}_{1}^{2}}{{\left(\dfrac{{R}_{1}}{2}\right)}^{2}}=4 \Rightarrow {g}_{2}=4g

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.
See it move: Gravitation and orbits simulationDrag the sliders and watch the numbers in this question change.

More Physics practice

JEE Main Physics practice question on Gravitation (Acceleration Due to Gravity), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.