Gravitation NEET PYQ – Previous Year Questions with Solutions

Q 1 :

A body weights 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 [2025]

32 N
36 N
16 N
27 N

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(4)

Given, $W = 48 N$ and $h = \frac{R}{3}$

Gravitational force at a height $h$ above the surface of the Earth, $F = \frac{G m M}{{(R + h)}^{2}}$

or $F = \frac{G (\frac{W}{g}) \times M}{{(R + \frac{R}{3})}^{2}}$ $[∵ Weight, W = m g or m = \frac{W}{g}]$

or $F = \frac{G \times 48 \times M \times 9}{g \times 16 R^{2}}$

Substituting, $g = \frac{G M}{R^{2}},$ we get

$F = \frac{48 \times 9}{16} = 27 N$

Q 2 :

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth? [2020]

48 N
32 N
30 N
24 N

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(2)

Gravitational force at a height $h$ ,

$m g_{h} = \frac{m g_{0}}{{(1 + \frac{h}{r})}^{2}} = \frac{72}{{(1 + \frac{R / 2}{R})}^{2}} or m g_{h} = 32 N$

or $F_{g} = 32 N$

Q 3 :

A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth? [2019]

100 N
150 N
200 N
250 N

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4

(1)

Acceleration due to gravity at a depth d,

$g_{d} = g (1 - \frac{d}{R})$

For $d = \frac{R}{2} \Rightarrow g_{d} = g (1 - \frac{R / 2}{R}) = \frac{g}{2}$

Required weight $W' = m g_{d} = \frac{m g}{2} = \frac{W}{2} = \frac{200}{2} = 100$ $N$

Q 4 :

The acceleration due to gravity at a height 1 km above the earth is the same as at a depth $d$ below the surface of earth. Then [2017]

$d = 1$ km
$d = \frac{3}{2}$ km
$d = 2$ km
$d = \frac{1}{2}$ km

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(3)

The acceleration due to gravity at a height $h$ is given as

$g_{h} = g (1 - \frac{2 h}{R_{e}})$

where $R_{e}$ is the radius of the Earth.

The acceleration due to gravity at a depth $d$ is given as

$g_{d} = g (1 - \frac{d}{R_{e}})$

Given, $g_{h} = g_{d}$

$∴ g (1 - \frac{2 h}{R_{e}}) = g (1 - \frac{d}{R_{e}})$

or $d = 2 h = 2 \times 1 = 2 km$ $(∵ h = 1 km)$

Q 5 :

Starting from the centre of the earth having radius R, the variation of $g$ (acceleration due to gravity) is shown by [2016]

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(2)

Acceleration due to gravity is given by

$g = {\begin{matrix} \frac{4}{3} π ρ G r; & r \leq R \\ \frac{4}{3} \frac{π ρ R^{3} G}{r^{2}}; & r > R \end{matrix}$

Topic Question Set

Q 1 :

A body weights 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 [2025]

Q 2 :

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth? [2020]

Q 3 :

A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth? [2019]

Q 4 :

The acceleration due to gravity at a height 1 km above the earth is the same as at a depth $d$ below the surface of earth. Then [2017]

Q 5 :

Starting from the centre of the earth having radius R, the variation of $g$ (acceleration due to gravity) is shown by [2016]

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Topic Question Set

Q 1 : A body weights 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 [2025]

Q 2 : A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth? [2020]

Q 3 : A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth? [2019]

Q 4 : The acceleration due to gravity at a height 1 km above the earth is the same as at a depth d below the surface of earth. Then [2017]

Q 5 : Starting from the centre of the earth having radius R, the variation of g (acceleration due to gravity) is shown by [2016]

Want Us to Email you About Special Offers & Updates?

Q 1 :

A body weights 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 [2025]

Q 2 :

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth? [2020]

Q 3 :

A body weighs 200 N on the surface of the earth. How much will it weigh half way down to the centre of the earth? [2019]

Q 4 :

The acceleration due to gravity at a height 1 km above the earth is the same as at a depth $d$ below the surface of earth. Then [2017]

Q 5 :

Starting from the centre of the earth having radius R, the variation of $g$ (acceleration due to gravity) is shown by [2016]