Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET 2013
Exam
NEET
Year
2013
Subject
Physics
Chapter
Gravitation

NEET 2013 · Physics · Gravitation

Infinite number of bodies, each of mass 2 ~kg are situated on x...

Infinite number of bodies, each of mass 2 kg2 \mathrm{~kg} are situated on xx-axis at distance 1 m,2 m,4 m,8 m1 \mathrm{~m}, 2 \mathrm{~m}, 4 \mathrm{~m}, 8 \mathrm{~m}, respectively from the origin. The resulting gravitational potential due to this system at the origin will be

Options

  1. A−G-G
  2. B−83G-\frac{8}{3} G
  3. C−43G-\frac{4}{3} G
  4. D−4G-4 G

Correct answer

D. −4G-4 G

Step-by-step solution

The resulting gravitational potential, V=−2G[11+12+14+18+…]⇒V=−2G[1+12+122+123…]⇒V=−2G(1+12)−1⇒V=−2G(1−12)=−2G(12)=−4G\begin{array}{ll} & V=-2 G\left[\frac{1}{1}+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\ldots\right] \\ \Rightarrow & V=-2 G\left[1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3} \ldots\right] \\ \Rightarrow & V=-2 G\left(1+\frac{1}{2}\right)^{-1} \\ \Rightarrow & V=-\frac{2 G}{\left(1-\frac{1}{2}\right)}=-\frac{2 G}{\left(\frac{1}{2}\right)}=-4 G \end{array}
Practice Gravitation on Quantrex Academy →

More from Gravitation

The amount of work done to raise a mass ' m ' from the surface of the Earth to a height… NEET 2026Two planets P_1 and P_2 with equal mass have radii R_1 and R_2 , respectively, where… NEET 2026In a solar system, the time-period of revolution of a planet tracing a circular orbit of… NEET 2026The radius of Martian orbit around the Sun is about 4 times the radius of the orbit of… NEET 2025A body weighs 48 N on the surface of the earth. The gravitational force experienced by… NEET 2025The escape velocity for earth is v . A planet having 9 times mass that of earth and… NEET 2024The mass of a planet is (1)/(10) th that of the earth and its diameter is half that of… NEET 2024An object of mass 100 kg falls from point A to B as shown in figure. The change in its… NEET 2024 Full Gravitation list All NEET PYQs