Gravitation - Result Question 15

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15. 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]

======= ####15. 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]

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/gravitation/gravitation—result-question-15.md (a) $d=1 km$

(b) $d=\frac{3}{2} km$

(c) $d=2 km$

(d) $d=\frac{1}{2} km$

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Answer:

Correct Answer: 15. (c)

Solution:

  1. (c) Above earth surface

Below earth

$ g_h=g(1-\frac{2 h}{R_e}) \quad g_d=g(1-\frac{d}{R_e}) $

According to question, $g_h=g_d$

$g(1-\frac{2 h}{R_e})=g(1-\frac{d}{R_e})$

Clearly,

$d=2 h=2 km$

Graph of $g, R$ and $d$ :

(i) $g$ at surface of earth is maximum

(ii) $g$ at centre of earth is zero

(iii) $g$ is maximum at poles and minimum at the equator.