back to directory
NEET PHYSICSGRAVITATIONEasy

Question

Assuming the earth to be a sphere of uniform density, its acceleration due to gravity acting on a body:

A

increases with increasing altitude.

B

increases with increasing depth.

C

is independent of the mass of the earth.

D

is independent of the mass of the body.

Step-by-Step Solution

  1. Formula for g: The acceleration due to gravity on the surface of the Earth is given by g=GMERE2g = \frac{GM_E}{R_E^2}, where GG is the gravitational constant, MEM_E is the mass of the Earth, and RER_E is the radius of the Earth .
  2. Independence of Body Mass: The expression for gg depends only on the mass and dimensions of the source mass (Earth). It does not contain the term mm (mass of the body). Thus, all bodies fall with the same acceleration, regardless of their mass . (Statement 4 is correct).
  3. Variation with Altitude: As altitude hh increases, the distance r=RE+hr = R_E + h increases. Since g1r2g \propto \frac{1}{r^2}, gg decreases with increasing altitude . (Statement 1 is incorrect).
  4. Variation with Depth: Inside the Earth (assumed uniform sphere), g(d)=gsurface(1dRE)g(d) = g_{surface} (1 - \frac{d}{R_E}). As depth dd increases, gg decreases linearly, becoming zero at the center . (Statement 2 is incorrect).
  5. Dependence on Earth's Mass: The formula explicitly includes MEM_E. Thus, gg depends on the mass of the Earth. (Statement 3 is incorrect).

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from GRAVITATION. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSGRAVITATIONassumingsphereuniformdensityacceleration

More GRAVITATION Questions

View all

The radii of the circular orbits of two satellites A and B of the earth are 4R and R, respectively. If the speed of the satellite A is 3v, then the speed of the satellite B will be:

A.3v/4
B.6v
C.12v
D.3v/2
EasySolve

A black hole is an object whose gravitational field is so strong that even light cannot escape from it. To what approximate radius would earth (mass = 5.98 × 10²⁴ kg) have to be compressed to be a black hole?

A.10⁻⁹ m
B.10⁻⁶ m
C.10⁻² m
D.100 m
MediumSolve

A body projected vertically from the earth reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest:

A.at the instant just before the body hits the earth
B.it remains constant all through
C.at the instant just after the body is projected
D.at the highest position of the body
MediumSolve

The figure shows elliptical orbit of a planet m about the sun S. The shaded area SCD is twice the shaded area SAB. If $t_1$ is the time for planet to move from C to D and $t_2$ is the time to move from A to B, then:

A.$t_1 > t_2$
B.$t_1 = 4t_2$
C.$t_1 = 2t_2$
D.$t_1 = t_2$
EasySolve

If the mass of the sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude, which of the following statements would not be correct?

A.Raindrops would drop faster.
B.Walking on the ground would become more difficult.
C.Time period of a simple pendulum on the earth would decrease.
D.Acceleration due to gravity (g) on earth would not change.
MediumSolve

The kinetic energies of a planet in an elliptical orbit around the Sun, at positions A, B and C are $K_A$, $K_B$ and $K_C$ respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S, as shown in the figure. Then:

A.$K_A > K_B > K_C$
B.$K_B > K_A > K_C$
C.$K_A < K_B < K_C$
D.$K_B < K_A < K_C$
EasySolve

At what height from the surface of the earth, are the gravitation potential and the value of $g$ are: $-5.4 \times 10^7 \text{ J/kg}$ and $6.0 \text{ ms}^{-2}$ respectively? (Take, the radius of the earth as $6400 \text{ km}$)

A.1600 km
B.1400 km
C.2000 km
D.2600 km
MediumSolve

A particle is released from a height $S$ above the surface of the earth. At a certain height, its kinetic energy is three times its potential energy. The height from the earth's surface and the speed of the particle at that instant are respectively:

A.$\frac{S}{2}, \frac{\sqrt{3gS}}{2}$
B.$\frac{S}{4}, \sqrt{\frac{3gS}{2}}$
C.$\frac{S}{4}, \frac{3gS}{2}$
D.$\frac{S}{4}, \frac{\sqrt{3gS}}{3}$
MediumSolve

This neet physics practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice physics sets →