JEE PYQ: Gravitation Question 18
Question 18 - 2021 (26 Feb Shift 2)
In the reported figure of earth, the value of acceleration due to gravity is same at point A and C but it is smaller than that of its value at point B (surface of the earth). The value of OA : AB will be $x : y$. The value of $x$ is:
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Answer: (4)
Solution
Point A is inside the earth, C is above. $g_A = g_C < g_B = g$. At depth $d$: $g(1-d/R)$. At height $h$: $\frac{g}{(1+h/R)^2}$. From the figure: OA = $4R/5$ and AB = $R/5$, so OA:AB = 4:5. Hence $x = 4$.
BETA
