Practice free Gravitation (Physics) NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
Two bodies of mass $m$ and $9m$ are placed at a distance $R$. The gravitational potential on the line joining the bodies where the gravitational field equals zero, will be ($G =$ gravitational constant):
Null point: distance $R/4$ from $m$, $3R/4$ from $9m$. $V = -Gm/(R/4) - G(9m)/(3R/4) = -4Gm/R - 12Gm/R = -16Gm/R$.
A satellite is orbiting just above the surface of the earth with period $T$. If $d$ is the density of the earth and $G$ is the universal constant of gravitation, the quantity $\dfrac{3\pi}{Gd}$ represents:
$T^2 = \dfrac{4\pi^2 R^3}{GM} = \dfrac{4\pi^2 R^3}{G\cdot (4/3)\pi R^3 d} = \dfrac{3\pi}{Gd}$.
The mass of a planet is $\dfrac{1}{10}$th that of the earth and its diameter is half that of the earth. The acceleration due to gravity on that planet is:
$g_p = (1/10)(2)^2 g_e = 0.4 \times 9.8 = 3.92$ m/s².
The minimum energy required to launch a satellite of mass $m$ from the surface of earth of mass $M$ and radius $R$ in a circular orbit at an altitude of $2R$ from the surface of the earth is:
$E_\text{orbit}(3R) - E_\text{surface} = -GMm/(2\cdot 3R) - (-GMm/R) = 5GMm/(6R)$.
The radius of Martian orbit around the Sun is about 4 times the radius of the orbit of Mercury. The Martian year is 687 Earth days. Then which of the following is the length of 1 year on Mercury?
Kepler: $T\propto r^{3/2}$. $T_{Mer} = 687\times\left(\tfrac14\right)^{3/2} = \dfrac{687}{8} \approx 86 \approx 88$ days.
A body weighs 48 N on the surface of the earth. The gravitational force experienced by the body due to the earth at a height equal to one-third the radius of the earth from its surface is:
$W' = W\left(\dfrac{R}{R+R/3}\right)^2 = 48\left(\dfrac{3}{4}\right)^2 = 48\times\dfrac{9}{16} = 27$ N.
Ready to ace NEET?
Free access · No credit card required
Yes. You can attempt every Gravitation question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.
No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.
The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.